The generator matrix

 1  0  0  1  1  1
 0  1  0  1  a a^2
 0  0  1 a^2+2a+1  a 3a^2+3a+2

generates a code of length 6 over GR(64,4) who´s minimum homogenous weight is 28.

Homogenous weight enumerator: w(x)=1x^0+840x^28+105x^32+10752x^35+11760x^36+168x^40+121856x^42+75264x^43+41160x^44+238x^48

The gray image is a code over GF(8) with n=48, k=6 and d=28.
This code was found by Heurico 1.16 in 0.367 seconds.