Study Abroad

Yes, you are eligible.

Some of the best colleges are:-
Stanford University. University of California - Berkeley
Harvard University. UCLA (University of California Los Angeles)
University of Michigan - Ann Arbor. Yale University. University of Illinois - Urban Champaign. Massachusetts Institute of Technology

You do have specialised courses in civil as Geo technical, construction management, structural engineering and so on. Because of the specialisation, you become more employable. You also save one year of your life as it is 3 years programme in UK.

Yes, you can get it. However only the course director can take decision as they have to check weather you have covered all necessary topics in your course. You need IELTS or PTE to prove your English proficiency.

Hello Rakesh,
Lateral admission or admission directly into second year of engineering after completion of Diploma is a very typical Indian phenomena. When you are thinking of studying abroad, I am afraid, lateral admissions are just not available but your Diploma studies will come in handy for getting you admission for an engineering course. Perhaps exactly on the same lines what IITs do in India.
Best wishes to you.

As long as your university is a nationally recognised certified university, there would be no problem in applying for studying higher studies abroad. So, definitely, you can.
All the best!

No, you will not be eligible for BITSAT as for the entrance, you need to be of Science background with PCM compulsory as this is an engineering entrance. So sorry for you.
Good Luck for the future.

Do you mean Post-Graduate studies in Business?

Well, that depends on the University and the course that you are pursuing. Different universities have different cut-offs. What you have to do is fix a course. Once that is done, check which University offers that course. The details can be obtained by Googling and the information regarding the cutoffs will be obtained in the respective websites of the universities.
All the best.