Heyy Chandan....

You can do the M.Tech in Energy Engineering as it's for the one who has done bachelor's in mechanical engineering. Visit the below link , you'll get a PDF of cucet where search out for it and check out it's seats available and criteria :

https://www.google.co.in/url?sa=t&source=web&rct=j&url=https://www.cucetexam.in/Document/Eligibility_Criteria_CU_JHD.pdf&ved=2ahUKEwi64Iaqq5jfAhUIpo8KHQTfAfIQFjAMegQICBAB&usg=AOvVaw2GkGH_CgQouzJhM2meCR8V&cshid=1544550809192