You may have 3 months or one month to find a job

If, unfortunately, you receive RFE in the middle of job seeking, you should rush to get an offer and provide employment verification letter. A small gap is tolerable before the new employment, as CIS would mainly consider if you do have a job to assure that you are still working or be willing to work in the same field.
Per CIS rule, you should have a job offer when to reply to RFE.