Purchasing a property with illegal bathroom

[Carlos Rodrigues]

Okay I know I asked a different question earlier but I have another one considering anther situation. So this Multi I want to offer in Kearny New Jersey (NJ) has an illegal finished bathroom in the basement and finished rooms. So when it comes down to property inspections and appraisal what will or could happen when they catch the illegal bathroom and finished rooms? What can the seller do to get away with it?

Thank you in advance!!