Yes, eZee Frontdesk has an option to add tentative/Unconfirmed booking. You can add tentative reservation by untick option for confirmed booking as shown in below image:

We can also set release period and minimum release amount % before arrival date for unconfirmed booking. Thus, If payment for unconfirmed booking is not received by end release period& release period is elapsed, Unconfirmed booking can be voided or cancelled during night audit at the end of arrival date.