Got some resolution. Commented out following code present in wp-config.php
/*$base = '/';
define('DOMAIN_CURRENT_SITE', 'domain.com' );
define('PATH_CURRENT_SITE', '/' );
define('BLOGID_CURRENT_SITE', '1' );
define('NOBLOGREDIRECT', 'https://domain.com');*/
Still testing if everything is OK. But do we need this code for something else? Should I uncomment some part of it?
Thanks
Hemant