I have 5 duplicate domains

A question to TECH specialists out there:A client has 5 duplicate domains with indexed pages from each of them. Basically this: - dup-domain-1: About 12, 000 results (No Referring domains) - dup-domain-2: About 7, 670 results (No Referring domains) - dup-domain-3: About 5, 930 results (5 Referring domains) - dup-domain-4: About 4, 930 results (No Referring domains) - dup-domain-5: About 381 results (1 Referring domain) The tech team told me that ‘route 53 redirection to all of these duplicate domains’. Also, if we add any content to our main domain the same landing page will be added to these domains. I cannot see the type of these redirects as all these search results return a privacy error message as all these old domains and their pages have SSL issues. Now to the questions: 1. What is route 53 redirection and why would they – the dev team – want it instead of 301 redirects? I obviously googled it, but still cannot really get it expert for the fact that is one of the Amazon services?? Is this correct?? 2. I also learnt the ‘You cannot create a HTTP 301 in Route53’ – is this true? If so, what does it mean from SEO point of view if we have all these above duplicate results with SSL issues that not using 301 redirects but route 53 redirection? Would all this have negative impact on the main domain? If so, how bad is it? 3. My original recommendations was to remove all these search results from the index. The dev team is asking me now either we should remove route 53 redirection? How to remove all these results from Google’s index? Remove route 53 redirection and simply add noindex to them instead of 301 as most of them do not have any values from acquired backlinks.