Section 80C states that you can claim deduction of principal repayment under section 80C only if the income from such property is taxable under income from house property i.e. it is owned property and you have the possession. Since you don't have the possession you won't be able to claim deduction of principal or interest amount.
So I guess if the cases reopen they will disallow such deduction.
Regarding legal expense it is to state that whether or not you can claim legal expense depends on nature of income if you are only earning salary income you won't be able to claim deduction of such income. However you may claim it as deduction against the interest you have earned from the builder under income from other sources.
However you will need the receipt from advocate because generally whenever there are any such expense in income from other sources assessing officer asks for proof.
Therefore you can claim such expense against interest income but you will have to take the risk of not having receipt. You can take a chance if you have paid the advocate via account payee cheque.
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