The first main thing to open an educational institution is to have the basic thought on which it will groom the learners. For example, every shcool has its own batch with a message n that is the theme to work upon. So decide that first, and then bring all the things into the process.
For curriculum- you have to study and compare different syllabus n then decide accordingly for students under different categories. Only a little difference you can bring here. In co-curricular activities & extra-curricular activities, you can show great differences.
What faculty you appoint will again add to the outlook of your school. What teaching aids you bring into your school is again a major area to think upon.
Registration-must required from CBSE/HRY board and I think you will take few years to get that.
ICSE board has a different syllabus pattern but that I dont know whether one can get the affiliation of this board here in haryana or not.
Rest, its very nice to hear about this from you, my friend.
Goodluck!!