Mom passed 2015 Can I get siblings to sign contract if no probate

[Renee B.]

I found a house the mom passed away in 2015, they're 10 siblings, NO Will & the property has an auction date. 

Auction date was 2/24/2020 Courts closed due to virus.

I wanted to buy the property before the auction date. Without probate can I have them sign a contract? and who signs the contract? all 10 of them? Seller's said could not afford attorney. Do the siblings have to get permission from Dade County to sell the property. Please help