I have diploma in thermal power plant of engineering.&technology. And I am doing job, and want to do graduation with job.

I think graduation with job is not possible . You can check some online post diploma courses or some part time courses. Engineering courses in distance mode are not allowed by UGC/AICTE at present. You can however go through this link :- http://www.nptidelhi.net/courses-offered--admissions.html Good