InSe K point

[Sam Rice]

Dear all,
I tried to create 3*3 InSe nanosheet(unitcell is attached ), but when I put the structure for relaxation, I need a lot of time (more than 8hours),  I changed K and  I realized that the main reason is K(reduced until 5 hours), but unfortunately I could not find the suitable k for this structure.please help me, I attached my structure

[Ulrik G. Vej-Hansen]

The only way to figure out how many k-points you need is to test how the properties, which you are of interest to you, converge with respect to k-points.