What is ground state electron configuration of W3+?
Electron configurations depend on the atomic number (total number of electrons in ground state) and oxidation state of an element.
For elements not in ground state, oxidation states should be taken into consideration. Oxidation state with "n+" means removing n number of electrons from the total number of electrons of the ground state element. "n-" on the other hand means adding n number of electrons. Then simply use this to obtain its electronic configuration.