Any one knows where is this option , I went to Admin cosole system management system properties but don't see this option
Yes, this is possible. In your community when you first login click "Invite people to join" from the Actions menu. From the "Send an invitation" screen that comes up, Note that this is limited to 50 people by default but you can modify these system properties on Admin Console > System > Management > System Properties to change that.
invitations.max.count is the number of invitations that can be sent within the specified period
invitations.max.count.period is the number of miliseconds before the max count resets. ( Default is 86400000 miliseconds, which is 1 day ).
Worked thank you thank you so much , worked , I added them to properties and then increased the limit , what a feeling to get it working