Colleges in Telangana

Refer this link: http://www.osmania.ac.in/sciencecollege/forsci.html.

Yes Pavithra, you are eligible for the course. PGDM in ABM is just like any other MBA/PGDM program. We take in students of any stream from any college/university.
For this year, admissions are over. If you want to try for next year, then start preparing for CAT. Give the exam in the month of November. Fill MANAGE application form that will be available till December 31, 2019. Appear for essay & GD/PI in the month of April 2020, if you are successful, then you will be the part of 24th batch of MANAGE, PGDM-ABM Program.
Keep striving for excellence!
For more details visit: manageites.org

Yes, you can join. But, this is totally at the discretion of the college officials. You need to have valid reason for such a long gap in studies.

Yes, you may have a chance of getting into NIT-Warangal. Based on previous year cut-offs, it is quite possible that you can get it but make sure you keep a backup in your hand before waiting for 2-3 round of counselling.

NITs are a brand in itself. The faculty members you get in NITs have a very good standard and also the exposure you'll get in NITs and IITs are a class apart. Even the fee is also very low.
Now coming to DTU, getting into DTU is tough due to reservation for Delhi candidate but this college also gives you enough exposure.

No, there is no such age limit mentioned on the official website.

You need to have a minimum of 60% to be eligible.