How can i marry who is having same surname and gothram

Same gothram and surname relationship like brother and sister. It is not acceptable by VEDA SASTRAS and MANU SASTRA dharma shastra rules. 

Marriage between same gotra or surname is void in eye of law also  society does not recognize such marriages so drop the idea.

sir please atleast one solution please sir please

sir i cannot live without my parents n my love both are important to me and i wont marry anyone except him

Dear All,

My Firend loving a girl and he cant live without her and so does she. He want to marry her. But here is a problem- she is his Father’s Father brother's Son daughter. Both of us Maternal and Paternal grandparent are different.  And there parents are against there relation. Her parents are looking groom for her and may fix her marriage with him soon. he do not know what to do. No one is with him to whom he can ask for help or even share his pain.He's in deep depression now. He cant live without her. He cant imagine his life without her.

So he's asking to all of you is there any way to agree them? they are in relation from paternal side not from maternal side. This relation is permitted in many hindus? If you have any link or you know any where in shastra or vedas mentioned that this relation is not prohibited please provide it to me so that she could argue to her parents. please help them please.