At the end of power planning, you can do the pre route DRC check using the command "check route drc $m -power_only".
Please don't use this command without the -power_only option as it may dump out off grid violations. The suggestion to use -power_only is also becuase, we would have routed only power nets. ( Expectionals - special data bus - this is design specific).
In case, if you landup with pre-route drc violations like notches, via overlap at the power planning stage, you can fix them using the following command
run route power2 post_route_refine $m
At the powerplan stage, you should not get a pre-route short/spacing violations. If you do get, please check your power structure. The run route power2 post_route_refine command may not help you to clean the pre-route short/spacing violations.
It may happen such that at power plan stage, you don't have pre-route drc violations, but they pop up after routing of signal / clock nets. You need to look into the drc violation through the drc violation browser and fix them.
Hope this helps.