Thx for your quick answer.

i was thinking about the same idea for your answer:

"You could noindex / disallow access to all but one website so that Google can't see lots of duplicates, but the sites are still going to be available to browse for a user."

The problem with this idea is that, the ISP might block the 'one website' (domain that we used to boost the SEO)  in the future. Which according to my knowledge we have to buy new domain aliases that is not blocked by the ISP and start all over again increasing the SEO for the new domain.

Is there any other solution for this?

yes we have the same content, basicly its the same root folder on server

Our company having multiple domain aliases (DIfferent TLD) like example.com, .net, .org, .club, .win to one site (Same Content). We do this because our country ISP is blocking a few of the domain aliases.

Question:

• Does this hurt the SEO rank?

• What approach is the best for us to gain SEO Rank?