Certificate

You should work somewhere in IT or some software developing in online, code contributing you need some of these experience or if you have experience then do what you want to study.

Minimum age 19 years | Maximum age 24 years
Candidate must be 10+2
Minimum height should be 155 cm.

For fee details, I request you to contact the college official or fill the inquiry form given on the website: http://www.relianceedu.com/

Yes, it is necessary.

It is going to be very difficult for you to get an admission in IIM Bangalore, without some good Work Ex and CAT marks, as IIMB gives graduation marks very high weightage in comparison to other colleges. And, after getting in you will actually need work extra hard to justify the lower marks in graduation that you have (but, with hardwork that is possible.)
Anyway, you can also look at IIM C and L which don't give as much emphasis to past acads.
Good luck.

Yes, income certificate is necessary.

Yes there are, 'Cisco CCNA 200-125 The Complete Guide to Getting Certified' is the best in my point of view. It is the course with the highest review ratings online and maximum CCNA experts recommend it. As well as the tutorial videos it also comes with complete lab exercises you can n on your laptop or desktop for free and easily, so you get a really good understanding of the theory and hands on practice too.