confusion in age for admission to school

Hi,
It is great to be associated with such a nice blog. I know there have been quite a lot of threads regarding this matter but I have few questions and would greatly appreciate some useful tips.
We recently moved from US to velachery, chennai and my son is 2 yrs and 6 months this april. I was wondering to join him in some play school but when i read most of the threads they have said by 2 1/2 the kids go to preschool, I am not sure if my son is ready as from the time we have reached abt a month ago he is quite sick and he is getting better but he is not fully potty trained.
Please answer my queries:
1. can he go to some play school now and by next year go to prekg, if so by the time he goes to lkg he will be 4 1/2. Will it be fine or will he be overaged?
2. please provide feedback on these schools :
Navadisha
abacus montessori
KYI- the school
3. Is PSBB millenium school shifting its lower classes also to porur?

4. What is the age criteria for joining in preschool in these schools

My son is very active and a quick grasper, lears things very fast. I want him to learn in an interactive manner and i do not want to push him.

Please advice me regarding these queries for the more I read I am more confused.


Sowdha