section 54

hello,
My friend has 3 residential property out of which 1 is self occupied, second is let out, 3rd is under litigation and 2 non residential properties which is let out

Now the 3rd residential property which was purchased 15 years back and is under litigation gets resolved and he decides to sell the property and purchase another residential property, can he still claim deduction under sec 54 by reinvesting the proceeds received from the sale on another residential property, is there any restriction on number of properties to be owned for claiming sec54

Please guide,