questions on costs of living in Kolkata (Calcutta)

Hello everyone, I might be moving to Kolkata next year with my husband and my 20 month-old daugther. I would be extremely grateful if some of you could provide me with preliminary information on living costs in the city of joy, such as average montlhy rent for a 2 bedrooms apartment in a nice area and average fees of Kindergartens. If you can also quote names of best pre-school institutions according to your own experience, it will be of great help.
Moreover, I'd like to know how you would assess the life in Kolkata for small kids and If you have any special suggestions in this regard, to make it safer and more enjoyable. Thank you very much for your attention and help
Raffaella