There are very specidfic rules regarding the claiming of dependents. Read the booklet on the filing instructions .
Remember, if your parents are dependent on you, they are likely overstays and potential public charges for inadequate resources and ties to their home country and should not be granted the priviledge of visiting the US due to their lack of ties to their home country.
You appear to be trying to commit fraud by claiming them as dependents for US tax purposes yet failing to properly declare that they are dependents for US immigration.