The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  3  1  3  1
 0  3  0  0  0  3  3  3 3a 6a+3  0  3 3a 6a+6  0 6a+3  6  3  3  3  0
 0  0  3  0  0 3a+6 6a+6 3a  6 3a+6  3 3a+6 3a 3a+3 3a+6  0 3a+3 6a+3 3a+6 6a+3  0
 0  0  0  3  0 3a+6  3 3a+3 3a+3 6a+6 6a+3 6a+6 6a+3 6a 6a+3 3a  0 6a+6 6a  6  0
 0  0  0  0  3 6a+6  6 6a+3  3  3 3a 3a  3 3a+3 3a+6 3a 3a  0  0  6  0

generates a code of length 21 over GR(81,9) who´s minimum homogenous weight is 126.

Homogenous weight enumerator: w(x)=1x^0+320x^126+1760x^135+3488x^144+5832x^152+6304x^153+93312x^161+12216x^162+373248x^170+16240x^171+13176x^180+5544x^189

The gray image is a code over GF(9) with n=189, k=6 and d=126.
This code was found by Heurico 1.16 in 23.5 seconds.