The generator matrix

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

generates a code of length 15 over Z7[X]/(X^2) who´s minimum homogenous weight is 63.

Homogenous weight enumerator: w(x)=1x^0+138x^63+918x^70+1656x^77+17682x^84+91332x^91+4338x^98+1584x^105

The gray image is a linear code over GF(7) with n=105, k=6 and d=63.
This code was found by Heurico 1.16 in 1.93 seconds.