Inter-Caste Marriage

Dear Sir/Madam, I am Mizanur Rahaman from Diamond harbor, west Bengal. I am Muslim but my partner is Hindu mondal .we know each other last 5 yrs. I am now 26 & she is just complete 21 by this march 2015. Now we are going to marry each other. There is no problem in my family. Her family is also know me well, they like me but when comes to marriage then they said " You are a good Boy we know you well, but what our society will say if our daughter marry with you". & this the problem. In-spite of all this i thought for future,if any mistake happen with our both family then we will be in trouble. Hence I want to go for legal help for our marriage. Here I want to know the process of marriage, is the marriage possible by Muslim marriage register office.Or special marriage is available in the muslim marriage registration office. or i should call for court marriage. Also please tell me the expenses. I know a advocate , he demand me 3000rs only his fees. & registration charges is extra. hence i request all of you, please help me out of this. Thank you Mizanur Rahaman