Hello,

BITSAT has kept the eligibility criteriafor BTECH(Hons.) as:-

1. must have PCM as major subjects
2. must have minimum aggregate 75%

as you said in your question that in average your don't have minimum 75%. This is a clear NO.  You can't give as you are not satisfying the eligibility criteria.

better to look for other top college. You can give JEE main and JEE advance to get an admission in top college of India.

you are eligible for that. if you have any categorical reservation then you can use it there to get your rank lowered which opens more scope for you.

Hope it helps!