I m doing analysis of exhaust system of KTM 390 rc. I'm facing problem with data input that i have to give to software (ansys) like fluent velocity pressure etc etc. From where can i get this information.

Something short of the speed of sound. If you're testing/developing, then exhaust gas temperature probes to get an accurate value. Then calculating the SoS is pretty straight forward.

Something in the range of 500 m/s is probably a good guesstimate. Pressure again, depended on the flow of the exhaust system, but anything over one atmosphere is typically detrimental to performance.

Would highly recommend this book:
https://www.goodreads.com/en/book/show/146015.Scientific_Design_of_Exhaust_and_Intake_Systems