Legal Question in Landlord & Tenant Law in California

Your father cannot be evicted until the expiration of his lease. Thereafter the relocation fees must be paid. There are different levels of payments. It is best of your father gets a consultation with a lawyer.

I am not an expert on LA rental regulations, but I believe he cannot be evicted even AFTER the expiration of the lease without just cause. That is the rule for most rent controlled units in most jurisdictions. Just cause is generally limited to failure to pay rent, other major breaches of the lease, owner moving themselves or close family into the unit (subject to STRICT rules) or the building is being taken entirely off the rental market, such as a condo conversion, or to be demolished and a new building built. The fact that they asked for an estoppel certificate also indicates that the buyers are intending to keep the existing tenants, since the entire purpose of estoppel certificates are to confirm to investors that the building they are buying has the cash flow from good tenants that they are basing their purchase on. So all in all it sounds very unlikely that your father is going to be asked to leave.