She can definitely get good colleges with this score into BSc.

Majority of colkeges solely consider class12th scores for admission.

Some of best institutions for Bsc across India shared below:
https://university.careers360.com/articles/ba-bsc-bcom

Students in top 4000 ranks have very good chances with all top colleges across India.

Hello,
Congrats to your sister. she got first class in 12th, so she is very much eligible for admission in degree. It depends upon her interest what to take next, whether she is interested in science or arts. If she is interested in science she can go for B.Sc in electronics and computers, physics, chemistry or statistics and etc. Let her decide what she can cope up with and based on her field of interest.