In Jain belief, there are 24 Tirthankaras. After they attain moksha (kevala jnana), they reside in Siddhashila, a liberated realm above the earthly universe. Therefore, no Tirthankar is located on earth today; their abode is in Siddhashila.

If you meant a specific set of four Tirthankaras and you want to know their individual identities or traditions (Digambara vs. Śvetāmbara), I can explain that difference and name the four you have in mind.