Hi,

Reputation wise BITS pilani is far better than IIITM Gwalior. You will get better environment, better exposure ,better overall development in BITS pilani.

But if your interest is in computer science then you can go for bio dual and get Cs as dual degree in second year.

But if you want to take dual then you should also consider the risk. You will have to work hard for one more year to get CS as dual degree. If you have enough faith in yourself that you can do enough hard work to get CS next year then only you should go for dual in BITS pilani, Otherwise go for IIITM Gwalior.

In my opinion you should go for BITS Pilani, it has much better reputation, placement, college infrastructure.

Hope this helps.

All the best.