hey anish,

for making weapons you can opt for chemical engineering , if you're interested in this field it is very good stream and quite interesting and many colleges in India offer this stream in this the field of B.Tech.

For a building space crafts you can opt for aeronautical engineering , this is pretigious course offered in the field of B.Tech

Both the fields are unique in their own ways, choose the best and the thing that interests you the best.

hope this helps

Hello Aspirant

Better to take Aerospace engineering for building aircraft s. Because in that you can develop the aircraft and space craft. Here two major branches were there Aeronautical and Astronautical engineering.Aveonics is similar but deals with electronics side of engineering.

For making advanced weapons you can choose nuclear engineering.it is about application of break down atomic nuclei (fission), for combining atomic nuclei (Fusion).

You can also take electronics and communication engineering for making advanced weapons and develop the weapons like electromagnetic bomb or E-Bomb.

If you have any other doubts let me know

Thank you!!