Hello, Yes, it is fine for your son to study in the USA and return.

For his admission into 11th class (Intermediate) in Telangana, you will first need to obtain an Equivalence Certificate from the Telangana Intermediate Board to prove his US 10th grade is valid.

For the TS EAPCET (EAMCET) exam, he will not be considered a "Local" candidate based on his own studies. However, he can still get the Local Candidate quota (85% of seats) if you, as a parent, can prove that you have resided in Telangana for at least 10 years. This is the most critical step. If you cannot provide this proof, he will have to compete for the more limited 15% "Non-Local" seats.