Srs

Can anybody explain me what are the contents of SRS.

There is no thumb rule which insists a specific content in srs. Contents are determined by many factors including existing environment, processes, complexity, volume, business nature, information available, etc. Here is the sample content index of a srs:
introduction
purpose
project scope
references
overall description
product perspective
product features
user classes and characteristics
operating environment
design and implementation
constraints
user documentation
assumptions and dependencies
system features
system feature 1
system feature 2 (and so on)
external interface requirements
user interfaces
hardware interfaces
software interfaces
communications interfaces
other nonfunctional requirements
performance requirements
safety requirements
security requirements
software quality attributes
other requirements
appendix a: glossary
appendix b: analysis models
appendix c: issues list

Following are the contents that are specified in the SRS, though it may be modified based on the needs.

Introduction
purpose
Project scope
References
Description
Perspective
Features
user classes and characteristics
Operating environment
Design and implementation
Constraints
Assumptions and Dependencies
External interface requirements
User interfaces
Hardware interfaces
Software interfaces
Communications interfaces
Nonfunctional requirements
Performance requirements
Safety requirements
Security requirements
Software quality attributes
Other requirements
Glossary
Analysis models
Issues