Chandni,
U get down at girish park metro station and walk towards Balika Shiksha Sadan School ( any one will guide you for it - just a 10 min walk from the metro station).
Near the school, there is one very old n known restaurant Food Castle, Just next building is a PG, many of my colleagues used to stay there. and from there you will get buses as well as metro facility to all the tuition centres...!
I am in chennai for my job, but basically from kolkata only... If you get a place there, it is safe as well as well connected to all places.....
Sorry i don't have the no. of that PG but the route is easy and you can go and find out yourself.
I hope this helps you
Regards
Madhumita