27 regular teams played against each other in the Ranji Trophy, 2005-06, after being divided into two different groups, Elite Group and Plate Group. The organisers of the tournament, Board of Control for Cricket in India (BCCI) put the teams into the two groups, depending on their performance in the previous year`s edition. The top 15 teams that played wonderfully in the Ranji Trophy, 2004-05 were put on the two sub-groups of the Elite Group, like Elite Group A and Elite Group B. The rest of the 12 teams were equally divided into the two sub-groups of the Plate Group, like Plate Group A and Plate Group B.

The teams first played in their respective groups for getting into the knock out level and then competed with two different aims. The teams of Plate Group played for getting promoted to the Elite Group in the next year`s editions and the Elite Group teams played for winning the coveted championship title of the tournament. The participating teams in the Ranji Trophy, 2005-06 included the likes of Andhra, Assam, Baroda, Bengal, Delhi, Goa, Gujarat, Haryana, Himachal Pradesh, Hyderabad, Jammu & Kashmir, Jharkhand, Karnataka, Kerala, Madhya Pradesh, Maharashtra, Mumbai, Orissa, Punjab, Railways, Rajasthan, Saurashtra, Services, Tamil Nadu, Tripura, Uttar Pradesh and the Vidarbha.

Ranji Trophy, 2005-06 Plate Group A Matches: The Plate Group A in the Ranji Trophy, 2005-06 saw the participation of 6 teams that were put in to the group, for showing poor performance in the previous year`s edition. The teams were not coming from any specific region of India and most of them were actually representing various Indian states in the most popular domestic cricket tournament of India. The teams included the likes of Goa, Orissa, Tripura, Saurashtra, Vidarbha and Himachal Pradesh and they competed with each other for becoming one of the top two teams in the group. The teams also gave their best efforts to secure a berth in the knock out level of the Plate Group and the teams like Orissa and Saurashtra eventually did so from the Group A. The Orissa and Saurashtra teams earned the highest points from the group matches to do so and they also competed with the top two teams of the Plate Group B for the Plate Group championship.

Ranji Trophy, 2005-06 Plate Group B Matches: The 6 teams that played against each other in the Plate Group B of the Ranji Trophy, 2005-06 were coming from different parts of India. The teams were mainly representing different Indian states in the most popular and premium domestic cricket tournament of India. The teams included the likes of Assam, Kerala, Jammu & Kashmir, Jharkhand, Madhya Pradesh and Rajasthan and they competed with each other very hard for becoming one of the top two teams in the group. The teams also gave their best efforts for securing a berth in the knock out level of the Plate Group and the teams like Rajasthan and Madhya Pradesh eventually did so from the Plate Group B. The teams earned the highest points from the group matches and competed with the top teams of the Plate Group A for becoming the champion of the Plate Group.

Ranji Trophy, 2005-06 Elite Group A Matches: The Elite Group A of the Ranji Trophy, 2005-06 saw the participation of the top most 8 teams in the tournament and the BCCI selected the teams according to their performance in the previous edition. All the teams performed very well in the previous edition of the tournament and they were not coming from any specific region of the country. The teams included the likes of Delhi, Mumbai, Maharashtra, Bengal, Railways, Karnataka, Tamil Nadu and Gujarat and all of them tried their best to claim one of the top two spots in the group. Securing a berth in the knock out level of the Elite Group was also another principal aim of the teams. However, only the teams like Bengal and Mumbai eventually became successful to do so from the Elite Group A. After earning the highest points from the group matches, the two teams went on to compete with the top teams of the Elite Group B in the knock out matches. The main aim of the teams was to clinch the prestigious championship title of the tournament.

Ranji Trophy, 2005-06 Elite Group B Matches: The Elite Group B of the Ranji Trophy, 2005-06 saw the participation of 7 teams that were coming from different parts of India. All the teams played quite well in the previous edition of the tournament and that is why the tournament organisers, BCCI put them in the Elite Group B. Most of the teams were representing various Indian states in the most prestigious domestic cricket tournament in India and they included the likes of Andhra, Baroda, Punjab, Services, Uttar Pradesh, Haryana and Hyderabad. The teams played against each other in the group matches with the same view of becoming one of the top two teams in the group so that they could secure a berth in the knock out level of the Elite Group. The teams like Baroda and Uttar Pradesh eventually became successful to do so from the Elite Group B, by earning the highest points from the group matches. They also competed with the top two teams of Elite Group A in the knock out level for winning the coveted championship title.

Ranji Trophy, 2005-06 Knock out Matches: The top 8 teams from all the four sub-groups of the Elite and Plate Groups in the Ranji Trophy, 2005-06 were promoted to the knock out level of the tournament. The BCCI promoted the teams on the basis of the points that they earned from their respective group matches and the top two teams from each of the sub-groups got the promotion. The teams included the likes of Bengal, Baroda, Mumbai, Uttar Pradesh, Rajasthan, Orissa, Saurashtra and Madhya Pradesh. The first four teams played against each other in the Elite Group knock out matches with the aim of winning the coveted championship title of the Ranji Trophy, 2005-06. On the other hand, the rest of the four teams played in the Plate Group knock out matches for claiming one of the top two spots in the Plate Group. The teams tried so because the top two teams of the Plate Group got the promotion to the Elite Group in the next year`s edition.