Hi when i am running dynamic analysis (earthquake)dynamic eigensolver stops after frequency 6. What should i do proceed with analysis.

Three conditions will cause the eigensolver to stop: 1) you have reached the mode cutoff (is it 6? the default =0 meaning it is not used), 2) the frequency cutoff (is your sixth mode greater than your frequency cutoff? the default is 33 Hz), 3) something's wrong.
The first two items are specified in your Control Parameters tab. The third - review your data, have someone else check your data, or submit a support ticket though SmartSupport.

Hi I checked all control parameter Frequency is set at 33 and mode cut off at 0. When i cancel the dynamic analysis its giving me shift adjustment require warning sturm sequence failure, extended frequency range

Change the frequency cut-off to 50hz and see what happens.