first of all qualify GATE with good percentile and then u can apply there in various SRF/JRF seats.
You need to pass IIT JEE Advance and Mains Exam for getting admission any of the IIT's. for getting admission in desired IIT's you should have appropriate rank .
IIT kharagpur is the best IIT for mechanical engineering. IIT Delhi ranks second.
All the old 7 IITs.
You can get Metallurgy or Mining with a rank of AIR 6500. But you will not get admission in the old IITs. You have a better scope in new IITs.
You have to Clear the GATE Exam.
Currently, Various Engineering and Basic Science Courses are thought in IITs all over India.
They teach you the subject.
The rank expected with 141 marks is around 11000. You wont get admission into any IITs with such rank.
The IITs Institutes IIT Kharagpur IIT Bombay IIT Kanpur IIT Madras IIT Delhi IIT Guwahati IIT Roorkee IIT Banglore New IITs IIT Rupnagar IIT Jaipur IIT Hyderabad IIT Bhubaneshwar IIT Gandhinagar IIT Mandi IIT Indore IIT Patna
IIT Delhi IIT Mumbai IIT Kharagpur IIT Kanpur IIT Chennai IIT Roorki IIT Gandhipuram
IIT,Delhi, IIT,Madras Birla Institute of Technology, B.S.Abdur Rahman University, P.S.G College of Technology
You can get into any of the 15 IITs of your choice.