@YASWANTH Manda

Did you follow the installation steps as per Install Pega Platform and  Configure a Postgres database for an installation ?

One possible cause of the error "Application at context path [/prweb] could not be started" could be related to the PostgreSQL JDBC driver.

If the required driver is missing or not properly configured, it might prevent the application from starting. In the case mentioned in the reference, the issue was resolved by copying the correct PostgreSQL JDBC driver to the appropriate directory and adjusting the privileges for the user in the database schema.

🌕 FAIL - Application at context path [/prweb] could not be started

The same error has been known to happen if there were not enough resources.  Please go through the Reviewing system and installation process requirements  to check available RAM. Other clients found if the infrastructure was not available to run pega instance this error occurred 

Also check Tomcat configuration .  Do you see errors like:: Address already in use: bind at sun.nio.ch.Net.bind0(Native Method). This would mean the connector port 8080 is already in use, try to change the port no. from 8080 to some other port number. This would not be a Pega issue.

If you still encounter issues I suggest that you log a new PSC Question with the title clearly indicating the error and version of Postgres you are using.

In the new question please provide an extract of the full install and startup logs.