Am I eligible for the M.E Nanotechnology after completing B.E Mechanical Engineering???

Yes you are eligible for the M.E Nanotechnology after completing B.E Mechanical Engineering, for admission in to the M.E Nanotechnology the applicant should have completed B.E Mechanical Engineering or its equivalent with good academic record.

Following are some colleges where you can apply to pursue M.E Nanotechnology:

Amity Institute of Nanotechnology (AINT), Noida( Uttar Pradesh )
Biosys Biotech Lab & Research Centre, Chennai( Tamil Nadu )
Indian Institute of Science : Center of Excellence in Nanoelectronics (CEN), Bangalore
Maulana Azad National Institute of Technology (MANIT), Bhopal( Madhya Pradesh )
National Institute of Technology (NIT), Rourkela( Orissa )
University of Madras : School of Physical Science, Guindy( Tamil Nadu )
Amritha Centre for Nanosciences (ACNS), Kochi( Kerala
Guru Jambheshwar University of Science & Technology : Dept. of Bio-Nano Technology, Hisar
Jamia Millia Islamia (A Central University), New Delhi( Delhi )
National Institute of Technology (NIT), Kurukshetra( Haryana )
Sastra University : Centre for Nanotechnology & Advanced Biomaterials (CeNTAB), Thanjavur( Tamil Nadu )
Jawaharlal Nehru Center for Advanced Scientific Research, Bangalore
Indian Institute of Science, Bangalore
National Chemical Laboratory, Pune
The IITs at Mumbai, Kanpur, Chennai, Guwahati and Delhi
Central Scientific Instruments Organization, Chandigarh
National Physical Laboratory, Delhi
IIT mumbai
IIT Kanpur
IIT Chennai
IIT guwahati
IIT delhi