My girlfriend parents are not agreeing for marriage because of the cars and religion

Dear Sir/Mam I'm from Bangalore and my girlfriend is from Andhrapradesh we both met in office worked in she worked for 6 months along with me understood each others then we started the relationship, she went back to her home town due to some emergency propose we thought we can convince our parents for the intercaste marriage, my parents have been agreed my parents spoke over the phone but her parents are not agreeing for the marriage they are telling that the caste and religion is a matter for me, they have taken her phone and there's no contact between me and her from past 8 months, her parents have threatened her that they will kill me if she gets married to me, they are looking for the alliance for her i recently met with an accident and I'm depressed very much by thinking of her, she is feeling afraid that her parents will do something wrong to me, I'm afraid of that she will do something wrong to herself i don't want that to happen, she is willing to get married to me but her parents are not agreeing to the marriage, her parents are strictly watching on her activities and she is not able to come out from her home and she dont have mobile to contact me as well, i want to get married with her and I'll take care of her very well but it's not getting understand to her parents, I'm confused that what shall be done next so next legally I'm not getting any ideas please give a legal suggestion to me that what can i do next please.