Fixed Deposit for leased amount of 10 lakh.

Yes. If the lease rent is repayable at the end of the lease term then the interest earned from the FD alone will be taxable under income from other source. (Only interest taxable)

If the amount is non-repayable at the end of the lease term then it has to be treated as Lease rent received and along with interest earned from the FD will be taxable under income from other source. (Both lease rent and Interest taxable)

If lease rent is for residential property then you can show lease rent under income from house property and Interest from FD under Other source. If other than residential property then treat as per above reply.

Yes mam. Its not necessary that you pay the same 10 lakhs. You can pay through any valid source and have the FD untouched. As the amount is refundable at the end of lease term its treated as loan and so no tax implication on the same. You just need to pay tax on the interest earnings if your total income along with the interest exceeds the minimum amount chargeable to tax (Basic exemption limit - 2,50,000 in case of resident individuals).