Yes, you can join Kendriya Vidyalaya No. 1 Tirupati. It's a central government school with CBSE syllabus. And to get into intermediate in KV you have to write an entrance test and on the basis of that you will get admission there. They focus on all round development and KV has good laboratories for the practicals as well. And you will not have stress to study 12 hours a day unlike in the other private institutes in Tirupati. So take your decision wisely.

All the best.