Eligibility to become a Supreme Court judge
To become a judge of the Supreme court, an individual should be an Indian citizen. The norms relating to the eligibility has been envisaged in the Article 124 of the Indian Constitution. In terms of age, a person should not exceed 65 years of age. To be elevated as a judge of the top court, a person should serve as a judge of one high court or more (continuously), for at least five years or the person should be an advocate in the High court or the Supreme court for at least 10 years or a distinguished jurist.
Selection procedure of Chief Justice of India
The senior-most judge of the Supreme court is generally considered for holding the office of the Chief Justice of India. When the incumbent CJI is about to retire, the Ministry of Law, Justice and Company affairs use to seek the recommendation of the CJI to appoint the next CJI. After receiving the recommendation of the CJI, the Ministry of Law, Justice and Company affairs forward the issue to the Prime Minister who will further move the proposal to the President of India for the final approval.
Selection procedure of other judges in SC
The selection of the other judges in the top court comes when there is any vacancy. If a judge is about to retire or retires, then the CJI initiates the proposal and sends the recommendation to the Ministry of Law, Justice and Company affairs to fill up the seat. The recommendation of the Chief Justice of India (CJI) for the appointment of a Judge of the Apex Court should be formed in consultation with a collegium of the four seniormost Judges of the Supreme Court. After acknowledging the views of the four judges, the CJI sends the proposal for appointment to the Ministry of Law, Justice and Company affairs, which forwards it to the Prime Minister who further moves the proposal to the President of India for the final approval. After the assent of the President, the Secretary to the Department of Justice is set to announce the appointment and issue the circular in the Gazette of India.
Credit: https://www.financialexpress.com/india-news/how-is-a-supreme-court-judge-selected-the-process-behind-elevation-to-indias-highest-judiciary/1146722/
