School for my 3 years old

The schools in that area have very good reputations, seemingly well deserved, and the three I visited look pretty good.
Mandarin is a very handy language so perhaps it's worth checking out how many lessons are in which language before you decide.
Multilingual kids will have a lot of advantages in years to come, especially if English and Mandarin are on their list.

You can try Saint Laurencia, BIS, Penabur, Santa Ursula if you have a daughter, Saint John's to name but a few. They are all around GS, Paramount BSD area or try Ipeka international at Puri Kembangan.

All can be found online.

I'm pretty sure all the above have Mandarin lessons. BIS is nothing short of amazing. It has amazing prices as well, but, WOW, what a place!
The majority of the best schools have Mandarin lessons - a sensible option for the world as it's developing politically and economically at the moment, but some places run a lot of lessons in that language while others simply have it as a subject.

Thanks lukereg, ill check them all out.
BIS as in Binus School Serpong ?

BIS as in the British school. They might have dropped the word international.
I am not sure Binus has school for all all grades other than High school and University.

Binus, BSD has an SD.
Big school with lots of facilities. I'm pretty sure they have  a TK as well

BIS is in Bintaro sektor 9.

You should note that the Indonesian government has forbidden the use of the word "International" in school names and in 2014 the British International School changed it's name to the British School Jakarta.

Many other international schools simply replaced the word "international" with the word "independent" and some with the word "intercultural". However, they are still essentially international schools.

Yes that's correct. However searching for international schools Jakarta through a search engine will bring you to the intercultural schools links.