Science

Indira Gandhi National Open University offers post graduate Diploma in chemistry online.

The best colleges in Telangana or in South India are-
The Osmania University,
Guru Nanak University,
Nalsar University of Law etc.

AIIMS Delhi, K J Somaiya College of Nursing Mumbai etc.

If you want go in teaching then you do not need to complete B.Ed after MCA to be eligible for CTET. If you are looking at Computer teaching jobs like PGT or TGT in private or government schools then you can apply without appearing for B.Ed or CTET.

Yes, you can do B.Ed after B.Tech. Candidates are required to have a degree from a recognised college with a minimum of 50% marks.

Gujarat University .

You can refer to the link given below for cutoff-
https://www.shiksha.com/college/mount-carmel-college-palace-road-bangalore-24896/course-b-sc-botany-zoology-247365

You can refer to the link given below-
https://www.shiksha.com/university/bhu-banaras-hindu-university-varanasi-23336/cutoff

PGDM courses are industry oriented unlike MBA, which are more theoretical in nature. PGDMs focus more on grooming programs, mentorship and industry exposure. Also the placement services are more rigorous with PGDM programs. Hence, PGDM course from a recognised institute is usually good to pursue good salary options.

Yes, one can pursue MBBS after completing B.Sc. Zoology provided you meet the eligibility criteria set by the medical schools, only for that, you can plan to join. I hope it helps.