Unable to add a new connection to server in PostgreSQL using pgAdmin
It seem like you are connection via termial to port 5432 as command psql on terminal directly connect to default port 5432 

Try connecting to database via terminal using below

psql -p 5433


After connected, change user password 

alter role tars with password 'tars'; --if role in not present create one with create role tar with superuser; 
alter role tars with login;


now go to pgadmin and change the following :

on maintenance db put "postgres"
on user put "tar"
on password put "tar"


and try connecting if still kindly lemme know the below things :

1) Can u list contents of pg_hba.conf and postgresql.conf file ? 

2) Also how u changed port number via postgresql.conf or created another cluster ?