Colleges in Hyderabad

Shantiniketan vidhyalaya
Delhi Public School
St. Peter International School
Sreeneedhi International School
Jain International School
Sri swami Narayan GuruKul.

Sure, it is possible to do that. You need to have scored a good grades in B.Tech of ECE Field and also needs to be clear with all the tics and tactics to be evolved in the field that is most ravishing and dealing with the equations. But, it differs from university to university. There are Entrance exam for some of the universities.
Rule of admission:
Any candidate who has obtained Bachelor degree in any subject and has qualified at least 3 courses each of one year duration or 6 courses each of one semester duration in Mathematics securing at least 45% marks in aggregate will be eligible to appear in the Entrance test.
Best of luck.

Yes, MA Telugu is offered through distance mode.

No, there are more colleges apart from IBS. IBS is one of the colleges for MBA. You can also try for IIMs, Narsee Monji, Symbiosis, Xavier's, IMT, etc.

Of course, 85% marks are good enough to get St. Francis Degree College and if you don't get into the 1st list because of general category, just wait for 2nd and 3rd as you will definitely get it.
All the best for your bright future.