IIT

Based on the JEE Advanced rank you obtained, you can get the following colleges under OBC female category.
1. IIT Jammu (CSE)
2. IIT Bhilai (Electrical)
3. IIT Dhanbad (Mech. )
4. IIT Mumbai (Chemistry)
5. IIT Kanpur (Chemistry)
6. IIT Kharagpur & Roorkee (Integrated M.Sc. Chemistry)

Yes, you are eligible for M.Sc. Mathematics through IIT JAM. While not eligible for NIMCET. The eligibility criteria of NIMCET is given below. Eligibility criteria : (I) B.Sc. / B.Sc. (Hons) / BCA / BIT / B.Voc. (Computer Science/ Computer Applications) of minimum three years full-time programme from a recognised University with Mathematics/ Statistics as one of the subjects
or (ii) B.E. / B.Tech. from a recognised university.

For NITs, you need minimum of 75% in 10+2 and you need to qualify JEE Mains paper 2. For IITs you need minimum of 75% in 10+2 and you need to qualify JEE Mains paper 2 and 1 and then JEE advance and then AAT to be eligible.