Dear Sir, gift from relatives is exempt under the Income-tax Act and Maternal Aunt ("brother or sister of either of the parents of the individual") falls within the definition of a "relative". Thus, the gift is exempt in your hands and no tax is payable.
Calculation of capital gain on sale of plot:
The plot shall be deemed to be a long term capital asset since the period of holding of previous owner is also to be included (in case of gift, will etc.). In case of long term capital asset, indexation benefit is allowed while calculating cost of acquisition. Thus, the calculation would be as under:
A. Sale consideration: Rs. 33,00,000
B. Less: Indexed Cost of acquisition: - Rs. 6,02,000
(Indexed cost of acquisiton = Fair market value of property as on 01.04.2001*301/100)
(Assuming that the fair market value of property on 01.04.2001 would be Rs. 2,00,000 (a valuation report would be required from a valuer to calculate correct value as on 01.04.2001. Otherwise, the assessee can also consider the original cost of acquisition, that is, Rs. 1,00,000, whichever is more beneficial to the assessee)
C. Long Term Capital Gain (A - B) = Rs. 26,98,000
On Long term capital gain, tax is payable at 20% (Plus, surcharge and cess as per the applicable slab in which you are falling). Thus, tax would be around Rs. 5.39 lakhs (plus surcharge and cess).
Hope it would be helpful. Thanks!