A. Generally residential unit cannot be use for commercial purpose. Hence, make sure that your rental/lease agreement permits it . And make sure that if you live in an apartment, the bye-laws of the apartment association allowed you to run a playschool. As per the law only chartered accountant, yoga teacher and lawyer can carry on their work in residential premises by using 20% of the place.
B. Get permission from the local tehsildar (a no objection certificate), consisting of 4 forms: Form A, Form B, Form C and Form D. These will be to verify the ability of the owner / founder, fitness of the land for the purpose and safety inspections. This is a long and difficult process, and multiple licenses and procedures have to be complied with. For instance, you can get a Fire Safety certificate only after completing the Fire Safety inspections.
C.Next, you need to make an application to the Directorate of Education in your state, for which you need to show financial capability, create a public trust / charitable institution to run the school with, ensure that the land is in the name of the promoter (you) and maintain a Fixed Deposit in the name of the school as proof of financial strength. After you do this, your school will be recognized by the Government of this State. Starting a school without recognition is inadvisable. (Sources: VakilSearch is India)