The generator matrix

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

generates a code of length 12 over Z7[X]/(X^2) who´s minimum homogenous weight is 61.

Homogenous weight enumerator: w(x)=1x^0+378x^61+90x^63+882x^66+1890x^68+126x^70+4116x^72+5292x^73+3906x^75+54x^77+72x^84

The gray image is a linear code over GF(7) with n=84, k=5 and d=61.
This code was found by Heurico 1.16 in 0.0149 seconds.