Then you can always quit claim the house to an LLC and repeat to postpone the foreclosure proceeding.

Also if he just postpones again, Can I keep or reduce the deposit money for rental loss? 

You can try and buy the house but typically time is of the essence as usually the bank will not postpone the foreclosure.2.

You should inform the title company that you'll be assigning the deal to an end buyer, so they postpone the municipal/lien search but proceed with the title search to ensure there are no issues with the title.

You basically have 2 options. 1. postpone the foreclosure sale2.

I agree with @Chris Seveney: You won't know until the opening of the auction if the sale got postponed, canceled, bankruptcy, loan modification, loan paid off or a number of other things have happened.If the "auctioneer", we use the term "Trustee", learns of a bankruptcy filing after the auction happens and if the bankruptcy is determined to be valid by the judge, then the "winning bid" gets their money back and it's as though the auction never happened.However, if the bankruptcy was not valid, the Trustee will determine if the winning bid proceeds or if they redo the auction. in my court house buying days occasionally ( this was oregon and Washington Vancouver market of WA.) the trustee would either record the trustee's deed or send it to us and I would run it over and record it..

. ;-)True story, I was dealing with Quality Loan Service as Trustee and negotiated a postponement and they wanted hard copy paperwork, wet ink, delivered to them. 

My first deal was postponed one week due to seller and this week was cancelled due to title company findings.

Secondly, check to see how quickly they update status changes (active to sold,  NOD to Recession, Auction date or postponement). 

A foreclosure can be postponed, again and again.