How can i define states in Jira other than default states and is there any effect if i create a new workflow

[sandhya]

According to  user requirements we need to create a workflow(not using default W/F).We need to create states and Transitions according to user needs.Is there any option to create states without impacting default states and Transitions.

[Udo Brand]

Yes, you can do it. Define your own statuses and your own workflow using these new statuses. It is all documented here: https://confluence.atlassian.com/display/JIRA/Configuring+Workflow

[Steven F Behnke]

To add to @Udo Brand's answer, it is better to create new statuses than ever touching the default ones: I try to leave everything default and just build UP instead of modifying the normal JIRA stuff. I find it frustrating to go into a new installation and find resolved as a "To Do category"  IE: Resolvedblue

Transitions aren't really shared between workflows in a way that matters so no worries there.