From India, Mumbai
As such Shrikant has given you the reply. Two possibilities emerge from your post. First one is that as such your company has requirement at some another city or state. Therefore, the transfer could be normal. Second possibility is that your company wanted to remove you anyway. They filled the vacancy that arose because of your long absence. When you approached to rejoin, your transfer to another city or state is a ploy to remove you.
By the way, in the first sentence of your post, you have used the term "the process to re join the company". However, after a leave, be it a long leave like maternity leave, employees "resume" their duties and not "rejoin". There is no process as such. A smart manager should know on which date who is resuming duties. From your side, you could have sent just a mail or SMS stating that your maternity leave will complete on ____ date and you will resume your duties on the next day.
Anyway, when you receive the transfer order, you may put up application for the cancellation of the transfer owing to your family requirements. Approach to the highest authority. Possibly senior authority may show clemency and put on hold your transfer.
From India, Bangalore
From India, New Delhi