B.Tech

See, there is no such restrictions on the percentage to study abroad. You can score as much as you then it would be beneficial for you in getting scholarships.

Yes, you can apply for the B.Tech and I'll prefer you to take IT in your B.Tech as this will be very helpful in your near future and this will take 3 years as you have done Diploma so far forward and all the best for your studies.

For that, I'll prefer you to call the college admission desk as this doubt they will clear you appropriately as there might be some admission procedure is going on in the college and that is why they are taking some time to start the classes.

Depends on the college. But most of the seats dont exceed 50.

For 2nd year- 203000/-
For 3rd year & final year- 193000/-
College provide scholarship if you have 85% or more in 12th (PCM). You can also inquire for the diploma holder too for scholarship.

Yes, you can get admission with such academics record. I suggest you to take admission for B.Tech lateral entry. You can also consider CT University for decision purpose.

Changing University after a year is not possible as different Universities have their own set of rules and regulation. You will have to study from 1st year again. So, no universities will give you admission in 2nd year on the basis of doing 1st year from different year. However, you can change course after 1st year or change institute affiliated to same university.