what is port number 21 and 22 in winscp?

while we download the WinSCP server in the login details it is asking port number in different number base 21, 22 how can fix it.

I'm not sure I understand your question/problem.

Anyway, port 21 is used for FTP protocol (and FTPS with explicit TLS/SSL encryption). Port 22 is used for SSH/SFTP protocol. WinSCP automatically uses the correct port number, when you specify the respective protocol. Usually it is not necessary to specify the port number explicitly.