Polytechnic

You should submit the online application during the time of admission. Your allotment is based on your 10th marks. If you have completed ITI/VHSC you have more chances to get a government seat.

Directorate of Technical Education in most of states conduct Join Entrance Examination (JEE) for Diploma level courses. The minimum academic qualification to appear in JEE is a pass in the final examination of High School (with the subject science and maths-II) from recognized board or equivalent. You may look for details in your own Atate Government's website for details.

Hi,
You have to pursue B.Tech because that gives you growth, salary and professional degree but on other hand, after polytechnic diploma you have to complete B.Tech programme for further growth.
In many good companies, B.Tech degree always has been on high demand.
All the best.

Generally 'state diploma boards' offers in both modes. Go to your nearest polytechnic, your stream staff room and ask them.

Yes, you can easily change your stream because in all engineering stream 1st and 2nd years are almost same. So directly contact your institution's administration for this.

You should opt for a single course. What would you do if your exam for both the courses gets scheduled at the same time?

Bharati Vidyapeeth's Jawaharlal Nehru Institute of Technology, Barapada School of Engineering and Technology, Bhadrak, Dayanand Sagar College of Engineering Bangalore, Government Polytechnic College - Ahmedabad are some of those providing polytechnic in CS. All these mentioned colleges are reputed and rank good in India.

Hi Sonu,
After polytechnic or any other degree, your focus should not be entirely on the money. I know it is important but in the beginning you should be more keen on learning new things and gaining experience . A package of 1 lakh after polytechnic is not possible in fact people who have even completed their education from top B-Schools don't get this package.

Yes BHU conducts its own entrance exam for polytechnic.

You need to score a minimum of 60% marks in Diploma because most of the institutes offer admission on the basis of Diploma percentage:
For college details, visit the link mentioned below:
https://engineering.shiksha.com/distance-learning-engineering-in-delhi-ncr-categorypage-2-58-1-0-0-10223-1-2-0-none-1-0