Dear student 

Greetings 

Whatever weapons industry India has is in the hands of the public sector. You have the gun factories, ordinance and armament factories, all under the ministry of science and tech or defense. These organisations have their own independent recruitment process.

DRDO is an organisation that works in the field of development of weapon systems. It has undertaken development of many useful technologies associated with warfare.

Weapon systems require engineers from all streams including avionics and aerospace. NAL is another organisation that contributes to weapon engineering. HAL is one of the premier avionics and aircraft manufacturing outfit taht is deep into weapon systems.

There are many PSUs involved in ship building in Kochi, Karwar, Kolkata and other places which involve state of art weapon systems.

Most of these defense related organizations recruit standard run-of-the-mill engineers from electrical, mechanical, computer, telecom, production streams ( the list is not exhaustive . They often have vacancies for general graduate trainees as well as Scientist / Engineer posts)  through their own recruitment process. No they do not do campus because that would be unfair to other institutions I guess. However ISRO provides special BTech / MTech / Combined courses in Avionics and aerospace. Absorption isn't guaranteed. But graduating from that course gives you a head start for weapon engineering not only in India but abroad too.

Most of these PSUs involved in weapons and armaments / ordinance systems are involved in the latest state of art technologies. The latest Indian GPS system is more a weapon engineering initiative rather than a public utility.

Currently India is opening up its weapon industry to private and international businesses. They are slowly picking up their paces to compete with the psu organisations.

Hope this helps!