Exemption under 54F

1. Can a person avail exemption under section 54F if he invests in a residential house property by selling the shares held by him?

[a]what if he is already in possession of more than one property which is put into commercial use and income of such properties is being chargeable under the head 'Income From House Property'.?

[b]If Yes, could u refer please me a case law w.r.t such decision?

[c]if No, kindly substantiate.