After observed the problem, Checked the tool overhang,tool holder for any deviations in holder or tool.
Clamp and bolt checked for any deviations, but not find any problem.Tap in fixture is also ok.
Then analyzed the problem and decided that due to clamping not done correctly(Exact force)to the part in between clamp change in the process.
After this analysis clamping force cross checked and continued production. 