have been optimized using 25 h of actual observation data on the Crab Nebula during November 2012. When applied to the remaining data on the Crab Nebula, the above cuts yield consistent detection of a $\gamma$–ray signal at a sensitivity level of N$_{\sigma}$ $\sim$ 1.40 $\sqrt{T}$ (where T is the observation time in hours).

  Parameters                                                Cuts Value                                                  
  ------------ ----------------------------------------------------------------------------------------------------- -- --
  L                           $0.11^{\circ}$ $\le$ L $\le$ (0.1000 + 0.0520 $\times$ ln S)$^{\circ}$                    
  W                           $0.06^{\circ}$ $\le$ W $\le$ (0.0850 + 0.0160 $\times$ ln S)$^{\circ}$                    
  D             $0.50^{\circ}$ $\le$ D $\le$ (1.27 $\times$ cos$^{0.95}$$\theta$)$^{\circ}$ ($\theta$=zenith angle)     
  S                                                $\ge$ 310 dc (digital counts)                                        
  $\alpha$                                          $\alpha$ $\le$ 18$^{\circ}$                                         
  F2                                                        $\ge$ 0.35                                                  
  L/W                                                       $\ge$ 1.55                                                  
  ASYM                                                       $\ge$ 0.0                                                  

  :  Dynamic Supercuts selection criterion used for analyzing the $TACTIC$ data.

A well established procedure to extract the $\gamma$–ray signal from the cosmic ray background is to plot the frequency distribution of $\alpha$ parameter (defined as the angle between the major axis of the image and the line between the image centroid and camera center) of shape (L,W) and D selected events. This distribution is expected to be flat for the isotropic background of cosmic events. For $\gamma$–rays, coming from a point source, the distribution is expected to 