there is a full blog on parentree comparing ib and igcse ..... u can check that.
for icse board, in bhandup there r 2 school pawar public school and G.S. Shetty international. Pawar Public Admissions must have been completed by now, u can try G.S. Shetty. But they have not yet got affiliation. so you need to check on that. IB/IGCSE school are in mulund. u can check the blogs in parentree for comparison.
GS Shetty is still providing admissions but not that reputed coz a newbie. SSVRM is only for Mulund residents & not that good either. You can try Airoli schools - VIBGYOR is starting its first session & Euro admits only from Jr KG onwards.