In an element when the number of neutrons differs than that of protons, it is called an isotope. An ion is formed when an atom gains a net charge due to loss or gain of an electron.
Different isotopes are different versions of an element with the same number of protons but a variable number of neutrons. An ion is an atom that has had electrons added or removed to give an overall electric charge. It is therefore obvious that any isotope of an element can be ionised, as the number of neutrons has no effect on the electronic structure of the atom.