I have predicted SNP in 6 varieties of the wheat genome. the file contains following information

Chr         Pos     AllelG1 AllelG2 AllelG3 AllelG4 AllelG5 AllelG6
chr1A   1144466 T/T T/T NA  T/T C/C T/C
chr1A   1144582 C/C C/C C/C C/G C/C C/G
chr1A   1145616 A/A A/A A/A A/A A/A G/G

How is possible to estimate the level of genetic differentiation in one population.how we can calculate homo/ heterozygoscty from above data.