What do you mean by conservation of charges?
According to the Law of conservation of charge
“When two different bodies are rubbed together, both bodies get charged equally but with charges of the opposite kind.” Thus, the total charge of two bodies before and after rubbing remains the same.
Example: When an ebonite rod is rubbed with fur, the electrons from the fur are transferred to the ebonite rod and therefore the ebonite rod becomes negatively charged (due to gain of electrons), while the fur becomes equally positively charged (due to deficit of a same number of electrons). As the same no. of electrons are, exchanged by the ebonite rod and fur, the magnitude of charges main same but with opposite sign.