No, there are no charges or taxes involved in SIP rebalancing. SIP rebalancing simply helps you update the funds in your ongoing monthly SIP so that fresh investment starts going into the new recommended funds.
There are no switch, redemptions, reinvestments, etc involved and thus there are no charges or taxes to be paid.
We also have YouTube videos available for all the common FAQs on SIP and Portfolio Rebalancing. This will hopefully make it simple to understand the entire process and help clarify any doubts that you may have.