Hi Balaji
For on premise:
The default value for the session timeout is 20 minutes and this value can be configured in machine.config
file.
For PaaS:
For PaaS infrastructures use Factory Configuration to configure the session timeout.
For more info read:
https://success.outsystems.com/Documentation/11/Developing_an_Application/Use_Data/Sessions_in_Web_Applications#Session_Timeout
Regards,
Daniel