BCA

You can go for highly study like you can do MCA, MBA, etc. Or if you don't wanna to study now you can do job also by cracking interview of many companies like HCL, Wipro Infotech Ltd, etc.

Yes, depends on the programme and university admission requirements. It may be difficult to apply to US and Canada since you have a 3 year degree. Just check admission requirements, course requirements and proceed accordingly.

It's going to be difficult, since its not relevant to your prior academic background. Yes, you can look for Diploma or pathway courses or any foundation pre-requisite courses. You have to communicate with the colleges directly. Write to them.

For admission in BCA, you need to have 10+2 years of schooling from a recognized board CBSE or equivalent.

Which course are you asking for? Some courses take admission on the basis of merit, others through entrance exam.

This college is good when it comes about placement, but the main thing which matters the most in computer programming and application is about your passion and interest.
If you want to take admission in this college it is centralized (DAV College). - Forms come out in May.
Best of Luck.

Ambedkar Law College, Chennai does not provide BCA LLB. It offers BBA LLB. For the list of courses and other details check out the link below:
https://www.shiksha.com/college/dr-ambedkar-government-law-college-kuralagam-Chennai-44096.

You can apply for various internships available on the internet. You can also take help of Naukri.Com to get information on various jobs available according to your profile.

The minimum eligibility for getting into BCA is 60% in 12th. You are not eligible to apply for BCA.

Any institute will definitely not take, if you are having back in any of the exam. At first, you have to clear your graduation. And, it is really going to be hurdle for your career. Best of luck.