How to kill application runs in a specific port

If you are not able to run a application due to port erro,
Open a terminal

# netstat -tvlnp |grep lsnr

Output:
tcp 0 0.0.0.0:1800 23985/tnslsnr

This application runs in port no 1800 with process identifier 23985

# kill -9 23985

It will terminate the application