Son's cricket friends near his grandmother's all go to St. Marks Grammar, and now he has questions

He's spending a couple of weeks of the holidays at my mother's place in AS Rao Nagar while I juggle clinic and the baby, and he's found a gang of boys in her colony who play cricket every evening. Most of them are at St. Marks Grammar High School. Now he wants to know why he can't go there. We live in Banjara Hills and he's in an ICSE school, so a switch isn't on the table. But I don't want to brush him off with 'it's too far' when I know nothing about the place. What are the middle classes like there, and how do kids who join from other boards find it? Mostly I want to give him an honest answer 🙂