Hello Gautam

It totally depends on you, where your interest lies, both the branches are really nice and have great scope ahead not only in India but abroad also.

Metallurgy is a field which teaches you about the physical and chemical behavior of metallic elements,their inter-metallic compounds,and their mixtures, which are also called alloys. Metallurgical engineer are required in every industry and enterprises that produce, buys, sells refines or manufacture metals or metallic products.

Aeroscope is a field which deals with the development of airceaft and spacecraft, it has two major overlapping branches - aeronautical and astronautical. This Field of Engineering is very interesting as you deal with the aircrafts  and spacecrafts.

It totally depends on you. Mumbai can give you a lot of exposure with an interesting branch.

Madras can give you peaceful atmosphere to study and develop interest in metallurgy.

All the very best :)