industrial engineering,manfacturing engineering,manfacturing & industrial engineering are eqivalent to mechanical or not. if not what is the fututre forecast for these branches for placements. if got the above branches in iit delhi,khargpur where i have to prefer sir.

Actually mechanical is a very general kind of branch which includes study of all this branches. You will learn concepts related to industrial, manufacturing, etc all in mechanical. So at any point opportunities will be higher in Mechanical after btech because your domain is huge.
At the same time, if you choose industrial which is one specific branch of mechanical only, than during placements some companies may not prefer industrial enggineering grads.

So opportunity wise Mechanical is highest

Now study wise all are same only. First 6 semester are ditto same to same in all. slight here and there. And in 7^th and 8^th sem you study the specific in depth about your branch and also you do project in the same. Do a reseach on syllabus part once you will understand.

So syallabus wise all are nearly same.

I hope its clear.
All the best

Hi..
The branches you have quoted are all good.
Since these are not the core branches, so I wont be equating them to Mechanical engineering exactly. But, the study pattern and the placements are all good.
You should refer to the placement data for last two -three years for both IIT Delhi and Kharagpur.
To choose, you have to take into account other factors also like your interest and the ease with which you will be able to go with the subjects as well as your future aspects.
Hope you take a wise decission.
Regards