You can use any of the clocks mentioned above in the table (LPACTIVE mode).
In the LPACTIVE/LPSLEEP modes, the maximum device current should not exceed 25 mA (refer to the datasheet for min/max numbers). Firmware should
enable/disable blocks and reduce the clock frequencies appropriately to ensure power consumption does not exceed the limit.
If you have any doubts please feel free to ping a message here.
Is there a power calculator that i can use to estimate the active current consumption?
As far as I know, there are no power calculators. You can measure the current by connecting an ammeter to the J8 header on the PSoC 6 development board.
For power reduction you can turn off clocks which are not required.