The answer to your query depends on which country are you sending the powerlifters to.
Generally, being the organiser, you are required to safely escort all the participants of the powerlifting competitions to the respective countries, but you shall not be held liable any criminal activities committed by any of the powerlifters, if your direct involvement is not there.
So, there is no problem in charge fees for visa application, but at the same time you have to provide safety to the participants and be sure that they don't do anything stupid as laws in foreign countries are far more stringent than India.
For any other queries, feel free to call.