notice period negotiation

i joined my current company only 3 months back and i need to go to differnt company..my current company is saying I need to serve motive of 90 days as there is no probation period..my future company is expecting me to join by 45 -60 days..what to do..i have alread resigned.i told them i have mobdependency and can do all kt transfe rin 1 month max