Legal Question in Real Estate Law in California

Six months is a reasonable estimate, but you may be able to get it even shorter since the property is in Ventura, and you will be filing in Ventura. You can avoid some delays by having some legal assistance or hiring a skilled eviction lawyer to do the case. If you are going to have to evict the previous owner, you should be making a lower offer or getting a discount on the property that is owned by the bank.

I assume Mr. Roach means "Ventura County" rather than the City of Ventura.

I'd say six months is a little on the longish side to empty a home purchased at a foreclosure sale of its previous occupants. There is a difference between removing prior owners and removing occupants who are tenants of the prior owners, the latter enjoying some additional statutory protection. Also, the fact that prior occupants are still there post foreclosure sale doesn't necessarily mean they'll be tough to evict. The foreclosing financial institution may (a) have cut a deal with them to stay and take care of the place, (b) figure having the place occupied rather than vacant is to their advantage' or (c) be lazy, indifferent or preoccupied.

One possibility is to retain an eviction-assistance firm to handle the dirty work.

6 months is normal for Los Angeles County. It is a bit long for Ventura County.

You should require the lender evict prior to your purchase escrow closing.

If you can't accomplish that, then you should hire your own eviction specialist lawyer or 'service mill' in that area to expedite this. Do not try it yourself unless you know what you are doing. Asking your question demonstrates you do not.