Sir, pl tell me which one is the best for btech programming IIT or iisc ??pl do tell me the marks I require to get in mains roughly based on previous years analysis pl also inform about its location branches in Indian and also the courses or groups offered for ug program

As far as my knowledge goes if you want to do development and applications programming IIT’s are definitely better than IISC.
If you are interested in computer science research and mathematics of algorithms IISC is better in some sub-fields as compared to IIT’s
But overall programming exposure and opportunities in IIT’s are excellent.
You need to look at previous year cutoff’s for the rankings.

There are lots and lots of CS related courses int iIT
I am at IIT bombay so I can point to major sectors where there courses lies in

--- Theoratical Computer Science
--- Operating systems and databases
--- Algorithms design and research
--- Vision, Graphics and AI
--- Machine learning and optimization
--- Development and general programming