I'm sorry to say but characters can not be restored.
https://en.nostalrius.org/terms-of-useIII. Character/Currency/Item restoration
Nostalrius staff will not recover any lost characters, regardless of circumstances. We do not recover any lost items or currency except raid items with the rarity of Epic and above which can be restored in the case of a Server crash/roll-back, providing an in-game ticket is sent to us which fulfills the following conditions:
We will not restore the lost loot if the ticket does not meet all the requirements. Falsified information will lead to immediate account closure.
Exact date of the raid;
Screenshot of the raid ID;
Screenshot of the loot & complete list of raid members;
Name of the player who received the item.