service provide

services provided to an educational institution is exempt, by way of,-
(i) transportation of students, faculty and staff;
(ii) catering, including any mid-day meals scheme sponsored by the Government;
(iii) security or cleaning or house-keeping services performed in such educational institution;
(iv)services relating to admission to, or conduct of examination by, such institution;
upto higher secondary

if you provide one of these services, the. you cant charge GST

provide swing pool maintenance service

taxable
you should charge GST