India

The NCHMCT does not disclose the marks obtained. However, opening and closing ranks will declare. The ranks below 425 in general category is good enough for IHM-Pusa.

You have to focus your search in Sri City Nellore-Andhra Pradesh. The following MNCs can be the best option for you-
1. BFG International
2. ISUZU Japan
3. Astrotech Steels
4. MM Polytech
5. Free World Granites
6. Alstom transport
7. MIMCO DFS.

Check the list of all M.Sc in Chemistry colleges/institutes in India listed on Shiksha. Get all the information related to admission, fee, courses, placements, reviews & more on M.Sc. In Chemistry colleges in India to help you decide which college you should be targeting for M.Sc. In Chemistry admissions in India. https://www.shiksha.com/science/colleges/m-sc-chemistry-colleges-india.

Delhi have great exposure over Chandigarh. Further, the atmosphere of competition and preparation strategies of competitive exams like UPSE and GATE can be better manage at high pace in Delhi.

Chennai is better than Andhra Pradesh, and if you want best place, so it's Delhi there are many good coaching centers. Some good coaching in Chennai:
Singar Academy
Kew Academy
MT Educare.