To be eligible to be appointed as a Judge of Supreme Court of India, how long a person should have practised in a High Court?

Originally, the Constitution of India envisaged a Supreme Court with a Chief Justice and seven Judges; leaving it to Parliament to increase this number. Informative years, the Supreme Court met from 10 to 12 in the morning and then 2 to 4 in the afternoon for 28 days in a year. As the work of the Court increased and cases began to accumulate, Parliament increased the number of judges from the original 8 in 1950 to 11 in 1956, 14 in 1960, 18 in 1978, 26 in 1986, and 31 in 2008 current strength.