The generator matrix

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

generates a code of length 13 over GR(64,4) who´s minimum homogenous weight is 84.

Homogenous weight enumerator: w(x)=1x^0+280x^84+448x^85+28x^88+1960x^92+1344x^93+35x^96

The gray image is a code over GF(8) with n=104, k=4 and d=84.
This code was found by Heurico 1.16 in 0.000876 seconds.