Parents against love marriage

Hello sir, I am a working professional with an MNC at Pune . I am in love with my girlfriend from past 5 years. (I am jain and she is teli (a Hindu sub caste))We have a very good bonding and want to marry. However girls parents are not ready stating caste and society. Her parents are not even ready to give a thought to her happiness.they have tried all black magic Baba's and all to change her mind.we both are adults( both are 24 years old) recently her family members called me over phone and warning and threatened indirectly stating "have you seen sairat movie. And they will do that way to us" I m afraid they will hurt her. They have called me next weekend to their house "tu ghar aa phir dekh lete" they r emotionally n mentally blackmailing her. Since my mother needs a transplant surgery I cannot speak to parents as they are unwell will bp issues.. however they know that we want to get married and don't oppose ...please help me with legal direction so that I can proceed further. Girl is ready to go against her parents..but we wish if we cud settle all with all their blessings..please help