Diploma

Hi,
I am afraid you are not eligible. Your scores are too low for a conventional university. I would have suggested SPP colleges but they won't accept more than 5 backlogs. Please try any other country, may be Norway, Ireland, Belgium, etc. You may also consider vocational/professional courses in Ne

Hi,
You should opt for Masters from a university unless your career interest is somewhere else. Check the career outcomes and decide which one suit your future needs more.

You can pursue B.Sc but you have to start it from first year there is no provision for direct second year.
After diploma you can pursue direct second year engineering.

No, 10+3 means you have done 3 years Diploma in engineering which is equivalent to class XII, so you need to do graduation first. If you wish to do engineering further you can take admission in B.Tech 2nd year after giving Lateral Admission Test. After completing graduation you can go for MBA.

If you are looking for a college, you should take certain things in account.
Caste
State in which you are comfortable
Cut-off range of colleges
Best of luck!

Since you have already completed your undergrad it is advisable to go for higher studies like a Masters rather than pursue a Bachelors course again. However, if you want to change your line of study, you could opt for a B.Sc. You could also try getting some counselling to get a more accurate picture