The collegium system of appointment of judges primarily refers to a system where judges essentially choose judges. In India, the collegium refers to the 5 seniors most judges of the Supreme Court (led by the Chief Justice), who are the binding authority in all judicial appointments (transfer of judges, promotion of high court judges to the supreme court, etc.), and the government has no significant say in the decision-making process.
The National Judicial Appointments Council (NJAC) was a proposed body which would comprise of The Chief Justice of India, two other judges of the Supreme Court, The Minister of Law, and 2 eminent individuals selected by a comittee comrpising of the CJI, India's Prime Minister, and the Leader of the Opposition, with the aim of increasing legislative and governmental involvement in the selection of Judges.