A Nasik (= pantriagonal and diagonal) 12x12x12 magic cube does not exist. You can construct a simple, diagonal ór a pantriagonal 12x12x12 magic cube.

Simple

[Composite 4] Use a 3x3x3 magic cube & a 4x4x4 symmetric magic cube to construct a symmetric, 3x4 & 4x3 compact 12x12x12 magic cube, which is also 3/4 (in 3 of the 4 directions) pantriagonal magic.

Diagonal

[Composite 1] With a 12x12 magic square consisting of 2x2 proportional 6x6 magic square, you can construct a diagonal 12x12x12 magic cube.

[Composite 2] With a diagonal 6x6x6 magic cube you can construct a diagonal 12x12x12 magic cube and 1/2 rows/columns/diagonals in each level and 1/2 diagonals and 1/2 (main) triagonals give 1/2 of the magic sum.

Pantriagonal

[Medjig 3D]      René Chretien used the Medjig method to construct a pantriagonal 12x12x12 magic cube.

[Composite 1]  With a special composite 12x12 magic square you can construct a pantriagonal 12x12x12 magic cube.

[Composite 3']  With a 3x3x3 magic cube (and its reverse) and a symmetric pantriagonal 4x4x4 magic cube you can construct a symmetric pantriagonal 12x12x12 magic cube.

[Composite 5']  With a 3x3x3 magic cube (and its inverse) and a panmagic 4x4 square you can construct a pantriagonal 12x12x12 magic cube.