Patna

Hello Raja,
Yes, that's good. Still, there are many schools in Patna which give good results in class 12th. Some are:
1. St. Michael's School
2. B.D. Public School
3. Gyan Niketan
4. St. Karen's School

Super 30 is the best for the same.

Some of the best coaching institites can be considered to enrol as:
(a) IMS
(b) T.I.M.E.
(c) Career Launcher
(d) AMS
(e) BSC i.e.Banking services chronical.
However, coaching classes will just help you to equip the study contents easily. Self study is a key to qualify any competitive exams.

You can refer to the link: https://goo.gl/JO4Ez4

Hello Govind,
Here are few coaching institutes for NDA:
1. Kartar Coaching Centre
Makhania Kuan, Opp. PMCH
2. Vidya Kendra
The ScreeneX, Opposite Krishna Apartment, Boring Road
3. Vikash Coaching Centre
Radhika Complex, 1st Floor, Opp Alankar Place, Nearr Harihar Chamber, Boring Roadd Chauraha, Boring Roa

Hello Aditi,
Fee structure for BIT, Patna is around 11.5 lakhs for 4 years including hostels and placements is coordinated from Mesra, Ranchi campus so you have fair chances to get placed, you can sit in placement interview in all the 3 campuses.

Check out this link:
https://www.shiksha.com/bba/colleges/bba-colleges-patna