Data Flow Diagram , Process Flow, Use case diagram

Data Flow Diagram , Process Flow, Use case diagram and flow charts....they will fall in which category of SRS document? is it part of functional diagram or non-functional diagram; kindly elaborate with each type?

SRS contains complete description of system to be developed. It contains functional, non functional requirements and constraints related to system. But important point about SRS is that it doesn't offer design suggestions, possible solutions to technology or business issues, or any other information other customer's system requirements. No diagram is part of SRS document.

As you know that development of a system is divided into phases. Use-case diagram is part of requirement analysis phase. Whereas other diagrams like data flow, flow charts, state transition diagram etc provide different views of a single system. For example, data flow diagram provides system's view with respect to data. In broader perspective, you can say that each of these diagram represent functional view of a system. It is important to note that non functional requirements can not be depicted in diagrams.