English teaching schools

Hello

i am planning to move to OSLO some time around in November-December.I have two kids aging 9 and 4 years.

I wanted to know if
a)  If English speaking schools (Free) are available in  Oslo.
b)  What would be fees for them
c) What would be the language options available.
d) IB/IGCSE circulum available in schools ?

I just wanted to make sure that my kids wont have any problem if they come to india may be after 3-5 years should circumstances permit.

my kids are too young for me to have a lot of personal experience with this, but there's a private international school (expensive) and a public school that does an English/international program (not expensive)

the public school:
https://manglerud.osloskolen.no/

the private school:
http://www.oslointernationalschool.no