We started a migration batch containing 17 users  5 of them got migrated and the rest was stuck on syncing and they were syncing for about one week and a half we stopped the batch and deleted it. Now when we try to continue moving the other users they stuck on syncing with no email getting migrated whatsoever what can we do in order to transfer these user to the new server without having problems.

can someone tell me how to open a support case in order to get some help remotly

Hello

check moverequest logs with:

get-moverequest -ide username |get-moverequeststatistics -IncludeReport |fl

When you create the mailbox batch migration make sure you set the bad limit to like 100 or so that it ignores corrupt emails and continues syncing.