There is no prescribed format of application for seeking information. The application can be made on plain paper. The application should, however, have the name and complete postal address of the applicant.
For Central Government Departments, there is no form. You should apply on a plain sheet of paper like an ordinary application. However, many states and some ministries and departments have prescribed formats. You should apply in these formats. Please read rules of your respective state.
RTI stands for “Right to Information”. Right to Information is a fundamental right that every citizen has! Basically, the RTI gives you all the information that you want about the Govt. and what they are doing with your tax money!
You have the right to ask our Government, why the roads outside your house are not fixed? Why have you not received your “ration card” as yet? Why is there so much garbage in your area that is not picked up etc.