@RPLaks - You can try the below:
1. DAV Velachery (Parents must know Hindi)
2. SAN Academy (High Fee Structure 1.4 LPA)
3. DAV Adambakkam (But, you can secure seat if you're their community).
4. Don have an idea about St.Britto's
If you're on own house in Madipakkam, try getting application in all of the above. If you're in rent, better change the residence and move towards the City Limit like, Adyar, Besant Nagar, Thiruvanmiyur, Mylapore, Mogappair. You can find Top / Best schools there.
1. Chettinad Vidhyashram (Fee is high but the Quality of education is good)
2. BVM Adyar (Fee is high)
3. St.John's Besant Nagar - (Fee is comparatively low - Quality of education is good)
4. Hindu / Sankara - (Fee is comparatively low - Quality of education is good)
5. PSBB - (You can secure seat if you're their community)
6. DAV Mogappair/ Gopalapuram
7. Velammal Mogappair (Don go for anyother velammal (i.e.,) Newgen schools.
Choice of yours..!
Have heard good reviews about AGM school at Velachery. They had started their CBSE school - AGR Global - in a new building in their campus last year. Fees will not be too much. You can consider this school too.