Mechanical engineering is a core branch or what some people call an evergreen branch. While the placement of CS and ECE are better in most of the premier institutes, if you are interested in physics, mechanics, thermodynamics or such subjects a mechanical engineering degree can open up many research as well as well rewarding career choices. Of course a good institute helps a lot. All the best

Hello tejesh.
Mechanical Engineering is one of the most exciting and interesting branch of all branches in engineering.Most importantly it's one of the core branches.Yes, mechanical engineering definitely has a good scope , currently and in future.If you have genuine interest in the field,you should go for it without any doubt.You will learn all the interesting facts about machine and will handle it personally.As you know, future is all about machines.So yeah, it's one of the most promising branch , currently and even in future.Hope that helps.
Good Luck!