There is no need to worry. The first thing to do is meet the doctor for a check up on whether the tedious activities involved in a relocation, can affect your pregnancy. Most doctors would be against such travel at this time of maternity, especially if there are issues of blood pressure fluctuation or pregnancy related diabetes.
A medical certificate can then be issued by the doctor advising against travel and this can be submitted at the company.
With regard to confirming now on your joining at Bangalore, it is alright not to confirm on this stating that you would not be sure on the state of your health after delivery.
As for not providing the entire 6 months maternity leave, you can provide them a letter requesting for the reason as to whether they have any exemption under the maternity benefit act 1961. It is alright to let them know that you would like to check on this with the labour commissioner.
While the transfer of the employee from one location to other location is at the discretion of the employer, transfer at this juncture when the employee is running her 8th month pregnancy is not right. As per Maternity Benefit Act your employer is bound to sanction 182 days leave with salary and subsequent extension of one month leave if needed as per doctor advise.
Please keep copy of all the correspondences with the employer and make a firm request for Maternity leave as per Maternity Benefit Act. Even if employer suggests of 3 months maternity take it in writing and you can make a complaint to the Labour Inspector of your jurisdiction.
Hope you fulfill the eligibility criteria for Maternity leave as stipulated in the MB Act (worked with the employer for at least 80 days in the 12 months immediately preceding the date of expected delivery).
Also please don't be under stress as Mothers mind set is equally important at this juncture. Whether you get maternity leave with pay or not / whether you will be able to continue with your employment or not - these things doesn't matter. Please pay attention to your health and safe delivery which is more important than all above.
Hope you find this information useful.
If you have any other queries regarding any labour law compliance call me @8356832404