Where an assessee gets a favourable decision either before Appellate Authority or the Tribunal, whether the pre-deposit would be refunded back? Whether any interest is paid

Yes, where the assessee gets a favourable decision (fully or partially), the amount paid as pre-deposit would be refunded along with interest which is computed from the date of deposit till date of refund.
Further, Section 115 provides that interest at the rate specified under section 56 shall be payable in respect of such refund from the date of payment of the amount till the date of refund of such amount.

(ICAI FAQ PUBLICATIONS 06-09-2017 ORDERS OF APPELLATE TRIBUNAL: FAQ NO. 54)