I am jobless and being graduated from mechanical engineering and I am confusing in my career what should I do to get government job
See if you want to go for technical jobs then you can give the RRB Technical examinations which is for sectional engineer post or you can apply for ICRB examination for getting a post at ISRO for Scientist/Engineer. Apart from this you can apply for GATE examination to get into PSU's.
Apart from this if you wish to go for Adminstrative and Non technical jobs then you can appear for SSC CGL, RRB NTPC, UPSC CSE or state PSC. This examination are the most preferred examination for Government jobs.
Also you can apply for SBI PO and SBI CLERK which are for banking service.
I hope this answer helps. All the very best for your future endeavors!