Satish,
For a school to be affliated with a state, cbse,icse or whatever board, it needs to pass certain norms prescribed by the board, like the school area, number of students in each class, the principal's qualification and labs, libraries and such. most of the schools get into the groove only by the time the classes get to the 7th/8th. and some schools wait till they are eligible.
the school has to put its affliation number on the school name board display and also when it gives out ads.
sometimes some affliations are also revoked. so to know more about that, you need to keep track from the website of these boards
for the state raagini has given the link. for cbse, you could check the
affliation here. and f
or icse
Though the affliation guidelines are very clear and promising, i doubt how many schools follow them sincerely.