CBSE

You can either pursue modelling course for acting course after completing 12th. Refer to the link below:
https://goo.gl/1ZSt7n

Yes, the days are different and also the question paper.

Well, you can take the exam again or if you have passed all other subjects and failing only in two subjects then you can do engineering or any other course.

Not readily, they will hesitate to accept if you did not have a good academic record. You must write to a few universities and check. This applies to all the countries and not just UK.

12th marks is not the major criteria in selection of a good college, performing well in the entrance examinations only will help you out in getting a good college.

Hi Imtiyaz,
Yes, you are eligible to take admission for UG courses in Delhi University. The eligibility condition for UG courses are:
Candidates should be qualified in 10+2 Board or equivalent examination. They must have obtained at least 45% in aggregate of all subjects.
Further, for different courses, you need to clear the cut-off for admission.

Hi,
By clearing +2 certificate, you can do first Diploma Engineering followed by B.Tech in lateral entry in 2nd year. After B.Tech you can do MBA/PGDM cracking competitive exam for management entrance. But if we consider practical implementation of above route for you it is, though not impossible but difficult unless you become really serious, sincere and methodical in your study.

It usually comes out online in the mid of August. The last date is 15th Sept. Check the official website for more details.