The generator matrix

 1  0  0  1  1  1  1  1 5X  1  1  1  1
 0  1  0 5X+1  3 5X+2 5X 5X+3  1  6  1 4X+2 5X+6
 0  0  1 5X+5  3 5X+6 5X+1 5X+4 5X+2 X+3 X+2  X 4X+2

generates a code of length 13 over Z7[X]/(X^2) who´s minimum homogenous weight is 66.

Homogenous weight enumerator: w(x)=1x^0+756x^66+2520x^67+120x^70+2352x^72+9072x^73+12600x^74+108x^77+22638x^78+14112x^79+27216x^80+26040x^81+48x^84+66x^91

The gray image is a linear code over GF(7) with n=91, k=6 and d=66.
This code was found by Heurico 1.16 in 0.53 seconds.