B.Tech

Dear,
Both are good but nowadays VIT is better than LNMIIT but placement of LNMIIT is too good. Fee of VIT is too high.

Dear,
You may consider these options:
SRM
VIT
Manipal
Bits Pilani
JIIT
AMITY University
Bennett

Hi,
Some of the institutes in India offering B.Tech in astrophysics:
Aligarh Muslim University
Andhra University
Dr Babasaheb Ambedkar Marathwada University
Harish Chandra Research Institute
Indian Institute of Astrophysics
Indian Institute of Geomagnetism
Rashtrasant Tukdoji Maharaj Nagpur University
Aryabh

You can easily find the list of the best engineering college in all states on Google. It will be a bit difficult to clinch a seat with good branch and college but you can wait until last counseling. Some state also offers quota on the basis of sports and NCC, etc. So you can make a research and plan