How can I get mutual divorce and claim maintenance

Assuming that you two are Hindus, you can apply for a mutual consent divorce under Sec 13B of the Hindu Marriage Act.

Section 13B states that the parties can jointly move a petition for dissolution of marriage by a decree of divorce in the District Court on the ground that they have been living separately for a period of one year or more, that they have not been able to live together and that they have mutually agreed that the marriage should be dissolved. 

The Court shall then record the joint statement of the Parties and pass a First Motion Order giving a time of 6 months to the parties to resolve their dispute, however in case the parties are unable to resolve the issues within the stipulated time, the Court shall pass a decree of Divorce. So, therefore, divorce by mutual consent takes about 6-7 months.

The general rule is the divorce by mutual consent is filed by both parties jointly and their joint statement is recorded in the court which is signed by both in presence of their lawyers and the Family District Judge. This process is repeated twice once when the joint petition is filed also called first motion and after six months, which is referred as second motion. 

After this process is complete, Judge is satisfied with the consent of both for divorce all issues like custody of the child if any, permanent alimony and maintenance, issue relating to return of stridhan of the wife and settlement of jointly owned properties, divorce is granted. 

You should enter into a Settlement Agreement with your wife with respect to the terms and conditions of the divorce. This should specify the distribution of assets such as stridhan etc., maintenance/alimony payable by you post-divorce, that this amount would be a full and final payment and no party shall have any other rights as against the other party. And get this Agreement signed by 2 witnesses.