Chirec would be the best choice for you in Gachibowli. But i don't think you will get admission now. You can try in DPS and Chirec too for next year. You also have Meridian and Manthan International at Madhapur.
You can get right now in Sentia, Kennedy High Global,Creek, Vikas, Ladders Maharshi Vidya Mandir (MVM), Meridian and Manthan . These schools are around Miyapur/Kukatpally/kondapur/Bachupally/Madhapur
Some of the parents who are trying for admission in schools now have listed the above schools in this forum where admissions are open.
I think you can opt for Sentia. Meridian is good but a bit expensive. Likewise Manthan has also got good reviews. It has cambrigde curriculum along with CBSE for students right from PP1. You can have a look at it.
If you can go for a high fees structure, Oakridge will be excellent. It will be near ISB.
You can look for accomodation in Shipa park which is also called Green hamlet in Kondapur. It is near the Convention centre / Hotel Novotel. Just opposite to Shilpa Park is Maharshi Vidya Mandir. One of my friends stays at Shilpa park. You will be able to get a 3 bedroom flat in 12k to 15K. You can also look for accomodation in Malaysian Township near Kukatpally/Miyapur.
A lot of info has been exchanged on the above schools. You can use parentree's search engine to know the reviews .
You can opt for BVB (Bharatiya Vidya Bhavan)or JHPS (Jubilee Hill Public School)in Jubille Hills next year.
All these are CBSE schools.
I will list the websites of the schools mentioned above for your reference.
www.bvbpsjh.com Tel : +91-40-23544934.
There is Futurekids , an ICSE school from grade 1 at Puppalgua. If interested in ICSE, you can put him in this school from class 1 onwards.
The kindergarten is at jubilee hills. Admissions are closed now.