Hi

If you want to get into IIT you should choose science stream with maths group for your 10 + 2 i.e you should have physics maths and Chemistry. As to be eligible for IITs one needs to pass 12th with  Physics,  mathematics and anyone of the following subjects :-

-)Chemistry

-) or Biology

-) or Biotechnology

-) or Technical Vocational Subject.

Out of these, instead of choosing Biology or biotechnology etc  you should choose chemistry as in your JEE main and JEE advanced there is chemistry section in addition to maths and physics. Thus, you should choose science stream with physics chemistry and maths for your 10 + 2 and should also have one language subject like English or any other language.

Here's a brief of how you can get admission in IIT

Admission in Indian Institute of Technology IIT is on the basis of JEE advanced examination for undergraduate engineering courses

To be eligible for JEE advanced you need to clear JEE Mains examination first.

So for getting admission in IIT or joining IITs you need to clear JEE main first and then JEE advanced , the eligibility criteria for both the examination is given below:-

JEE MAINS

Eligibility criteria says that to be eligible for JEE mains 2021 for BE or Btech you just must be either appearing for 12th board exam or equivalent in 2021 or should have passed it in 2020 or 2019 with Physics, mathematics and anyone of Chemistry or Biology or Biotechnology or Technical Vocational Subject.

You can give JEE main examination for consecutive three years starting from the year of appearing for your 12th examination

You can get the details about it at
https://engineering.careers360.com/articles/jee-main-eligibility-criteria/amp

JEE ADVANCED

To be eligible you must qualify JEE mains and also need to pass your class 12th with at least 75% marks in aggregate in class 12 if belong to general or obc category or at least 65% marks if belongs to SC/ST or must be in the top 20 percentile in class 12 examination. For this year i. e 2021 this percentage requirement in class 12th has been lifted off

You can get the details about it at
https://engineering.careers360.com/articles/jee-advanced-eligibility-criteria

You can give JEE advanced examination for consecutive 2 years starting from the year of appearing for your 12th examination

If you manage to qualify JEE advanced then you can get admission in IIT on the basis of rank obtained by you in jee advanced examination by participating in jossa counselling

Thank you