Hello Santhosh, Courses categorized under Weapons Engineering: 

PG in Air Armament Engineering, PG in Combat Vehicles Engineering, PG in Guidance and Navigation Control Engineering, PG in Guided Missiles Engineering, PG in Microwave and Radar Engineering

Best colleges to study weapons engineering in India

• Defense Institute of Advanced Technology, Pune, Maharashtra
• Institute of Armament Technology, Pune
• College of Military Engineering, Pune.

Procedure - Complete a four-year degree course in mechanical, electronics, metallurgy, electrical or chemical engineering. (You can specialize in the weapons engineering only at the postgraduate levels)

 

For further query be free to contact... all the Best

Defence Institute of Advanced Technology, Pune offers a MTech in Armament and Combat Vehicles eligibility for which is a B.E/B. Tech degree in Mechanical / Production / Automobile Engg disciplines from recognized University
Apart form the above there is no such recognised university/Institute offereing a course in weapons/armament design. You will have to look for options to study abroad.