just browsing the net and i found this beautiful post regarding tab limits in CRM forms , originally posted here
Hats off to the original contributor.
hope its useful for the readers.
By default the max number of tabs allowed in CRM Form is 8.
You can change the count specified in the _iMaxTabs to increase the count as shown in the below screenshot.
Note: This is an unsupported change and it could be overwritten if you install Rollups for CRM.