Unfortunately, I don’t have access to Australian records, but the death is Victoria. I hope this helps.
Can't remember if this posted yet-The Argus [Melbourne], 18 June 1855: FFRENCH—ALDRICH—If Mark Ffrench, of Tuam, Co. Galway, Ireland, who arrived at Port Phillip in the Baretto Junior, in October 1853, will write to his brother-in-law, Charles F. Aldrich, Newcastle, N.S. Wales, he will relieve the painful anxiety of his friends, who have not heard of or from him since his arrival in the colonies. Or if any one has seen or heard of him, Mr. Aldrich will feel grateful if they would correspond with him, and address Newcastle, N.S. Wales. https://trove.nla.gov.au/newspaper/article/255613242?searchTerm=mark%20ffrench
Looking at Victoria's death index it looks as though Mark Ffrench died at Ararat Hos[pital?].