As there are much less seat in lateral entry in needed branch  then a diploma student can take admission in dtu through jeemain exam (as diploma is the equivalent of +2)

No, youwon't be able to do so because for admission in DTU through Jee mains Rank you need to give boards because that has weightage in calculating your AIR. 

Sir now +2 mark is no weightage in rank only how much are u gate in jeemain cosidear the rank

Oh i was in the thought that it will be implemented from next year.
Well in that case, the rule still stands. You need to have a 12th pass certificate. So the only option you have is to clear the lateral entry exam

As there are much less seat then can a  diploma student take admission in dtu (as diploma  equivalent of +2)  through jeemain exam

As there are much less seat then can a  diploma student take admission in dtu (as diploma  equivalent of +2)  through jeemain exam

If you take admission through JEE Main exam, you will be considered for admission to first year and not as diploma student. Only LEET is the exam that will consider you as a diploma candidate.Also, as far as I know, Diploma candidates applying for JEE main, have to then appear for advanced as well. Even then, you're not a lateral entry. They cannot get admission in NITs, IIITs and GFTIs because of the eligibility criteria of 10+2 score.I suggest consider other options where you can get through lateral entry.

Did computer science is lateral entry possible in DTU??