What is the current min. age requirement for Grade 1 ?

Hi,
Please guide me.As per my understanding,Education Ministry has passed/is going to pass a ruling that a child needs to be 4 yrs to get into KG1 (LKG).That means (s)he will get into Grade 1 at age 6.Thats what my kid will also be doing.
But,I'm finding certain schools that take in children at age 5 for Grade 1.Will that mean that my kid will be at a disadvantage later on..or have I taken the right decision?I think this is the most difficult phase of parenthood till date for me,finding a good school for my child!