Hello
Sneha mahure , If you are from schedule tribute (ST) category then approximately 40 or more than 40 marks are required to get admission in IIT and for giving advance exam you must be have the aggregate marks should be at least 65%. Candidates should be within the top 20 percentile ( category -wise) of successful candidates in their respective 12th standard (or equivalent) board examination.

Hope it will be helpful for you :)