how to fill a new column using some specific conditions

Table Details with new column position

I have this table in which contain two columns (1st = names, 2nd =Positions*). I want add a 3rd column titled"GeneName" which should have the "level" values according to $position column. As if the position value falls in any of the undermentioned class related GeneName should be written in the new column. 3 names to be filled in the new column are NIb, VPg and CI. Conditions are

NIb = from position 1014 to 2410
VPg = 3660 to 5563 and 
CI  = 5718 to 6282

please see the image attached for better understanding. Thanks