Opinion on change of job Profile & Relocation

Dear Sir/Madam, am working in IT company in Core Finance Team , recently my comp. has been acquired by some other comp. in the name of Integration new comp. is saying they want to centralised the activity which I am doing and saying you need to move to BPO division and has to work for the customer. or take transfer and go to other location. and after taking transfer they are not giving same work which I am doing. I have raise objection on moving to BPO Division this is new work for me also this is purely project base job. if customer withdraw the project than my job will also go. this will have diff. day & night shifts which will disturb my family will affect my heath too. I am living with my family not willing to move other city.my kids are studying in Delhi and my wife is also working. Need legal opening on this matter at this stage am not willing to fight with the company. but want to make some strong documentary proof if something goes wrong in future. your sincerely.