Hi aspirant

You cannot do anything except wait for the next year.

The eligibility criteria for IITs is as follows:

The candidates will have to satisfy at least one of the following two criteria for admission to IITs:

• The candidate should have passed 10+2 or equivalent examination with an aggregate of at least 75% marks. For SC/ ST and PwD candidates, there is a relaxation of 10% as they need the aggregate of minimum 65% marks.
• The candidates should be within the category wise top 20 percentile of successful candidates in their respective 12th standard (or equivalent) board examination.

• The scores secured in the following five subjects will be considered for calculating the aggregate marks and the cut off marks for fulfilling the top 20 percentile criterion:

• Physics
• Chemistry
• Mathematics
• A language (if the candidate has taken more than one language, then the language with the higher marks will be considered)
• Any subject other than the above four (the subject with the highest marks will be considered)

Yu can get college on the basis of JEE mains.And appear for the boards again so that you can get atleast 75%.

Use college predictor to predict your college on the basis of JEE mains score:https://engineering.careers360.com/jee-main-college-predictor

Hope this was helpful.