chances are bit dicey... Dont go upto LTT... get down at Thane or KYN... u may try KYN-DR-DDR-BVI local.. or simply take a bus from TNA to BVI... TNA to BVI will be approx 60 mins or 75 mins at max... local train option wl take upto 2 hrs...
or stl i would say extend ur buffer time... its bit difficult..