So I bought a property for 59k cash now there is a tenant that lives in the property so I get rent from that. I'm also doing a rehab on the house and the tenant is fine with that.

Now what I'm confused about is when should I call the bank to refinance should I do it after I'm done rehabing or can I do it during?

Also can you get a refinance offer before you even buy the property? for example let's say I saw the property for 59k and I see the houses near it are like 90K becaue they have a extra bathroom. Now can I tell the bank "Hey I'm gonna add a bathroom, is possible to get refinanced?"

You want to refinance after the rehab so you can capture the forced appreciation and the higher appraisal.