BCA

Hello Utsav,
Fundamentally Diploma courses were meant to impart skill based education so that you can earn a livelihood. Therefore after 10th.
However, since many students wanted to pursue graduation, it's recognised as equivalent to 12th class for many purposes.

Hello Utsav,
Diploma is at best considered equivalent to 12th class. Hence, you will have to do graduation first and then only, you can go for post-graduation.

It is a 3-year full time degree course for those who want to make their career in computers or information technology field.
If you have Maths in XII then you are eligible to pursue this course.

I think your interest in programming in different languages may best be utilized in BCA, a professional 3 years undergraduate course. It would be best to do it from a renowned Institute. After BCA, go for MCA. Industry recruits both BCA and MCA graduates.
Best wishes.

You are advised to seek admission in MBA to change your career stream. You are further advised to appear for civil services examination, CDS and paramilitary exam conducted by UPSC. You can also appear for SSC exam. You may appear for PO and clerical services examinations conducted by public sector banks.

You should concentrate on one stream as it will increase your chances to get admission in that stream.
Best of luck.

It can be around Rs.15, 000 to Rs.30, 000.

Hello Thankur,
You can check the below mentioned list:
https://www.shiksha.com/it-software/colleges/colleges-delhi-ncr?bc[]=33

BCA is a job oriented degree and you can opt for a job after completing BCA. It will be good, if you obtain some industry recognized certifications. However, for long term career in IT industry, you can also evaluate pursuing MCA. If you are not technically oriented, then you can opt for MBA.