PSEB

If you have more than 75 % you are definitely eligible for various type of scholarship in BCL. During law you must be planned and clear with your goal.
BEST WISHES.

The basic BCA eligibility criteria for the BCA admission process are mentioned below:
The student must have an aggregate of 50% or above in Class 12 in any stream (Arts, Science, Commerce) with English and Mathematics as a compulsory subjects. Some colleges grant admission to students who have completed class 12 without Maths and English as mandatory subjects. If you found it helpful then upvote or thumb up my answer. Good luck.

You can change the board from CBSE to PSEB, but you need to study in class 11th also for registration purpose. However, PSEB schools will take only the fee of class 11th and 12th during admission and will permit you for PSEB 12th board exam. Because you have not practically studied in 11th and 12th of PSEB schools, So, improvement in marks is not guaranteed because of different syllabus of boards. So keep remain with CBSE board.

Not now board has not reduced syllabus for Science stream.

You can download it from board's website.

You can apply for a visa to visit Australia. You can apply for an ETA using the Australian ETA app on your mobile device if you hold an eligible passport or you may also apply online for a visitor visa through ImmiAccount. European passport holders may be eligible for an visitor (subclass 651) visa.

No, it will not effect just concentrate on your studies and don't let your level and marks get down keep working hard and enhance your knowledge and percentage.

Yes, date had been extended till may be 20 May but now again change have been made its for sure that they are not cancelled yet they are postponed but till which date about this I have no knowledge. Be prepared and practice hard for your exams all the best.