for 1st degree Relatives its 5+1 =6months & for 2nd Degree Relatives its 1+2= 3months... so the 3month extension is for 2nd degree relatives...
It is certainly a rumor..
When the Visit Visa Law was changed, the 3 month grace period was removed, & that was almost 2yrs ago... so one could reapply for family visit visa as soon their family exits.