Can replicate make 1:1 clone?

really it depends on the kind of data your storing and replicating.

assuming nas1 fails and you have to get up and working with nas2 asap, you could do something like this, provided you have sufficient space on the backup device:

simply copy (not move) the data from the replicate backup share to a share same name as source, then point your users/dns/ip to nas2

for example:
source nas1 (192.168.1.101) share = //nas1/documents
replicate destination nas2 (192.168.1.102) share = //nas2/replicate/nas1/documents

nas1 fails
on nas 2, create share //nas2/documents
create frontview backup job:
- source local folder /replicate/nas1/documents
- destination local folder /documents
depending on amount of data, it should go pretty quick since its simply a local file copy from one folder to another
once data is copied to nas2/documents then you can either change your dns/ip from nas1 to nas2 so that nas2 appears as nas1 to your users.

this is all very simplistic, and many factors could complicate it, like if running AD or using local users, or if your replicating iscsi luns, and I'm sure other things depending on data and how you use it.