The generator matrix

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

generates a code of length 10 over GR(81,9) who´s minimum homogenous weight is 54.

Homogenous weight enumerator: w(x)=1x^0+1680x^54+2880x^63+14040x^72+472392x^80+22160x^81+18288x^90

The gray image is a code over GF(9) with n=90, k=6 and d=54.
This code was found by Heurico 1.16 in 4.68 seconds.