1) you can purchase the house by taking home loan
2) ) you must purchase the house within 1 year before the date of land sale or within 2 years after the sale.
3) There is no provision for tax exemption for LTCG if you repay the home loan taken for a residential house. However, you will be able to claim deduction under Section 80C in respect of the home loan repaid during the year along with other eligible items upto Rs. 1.50 lakh.
4) you can claim an exemption under Section 54EC by investing the indexed long-term capital gains in capital gains bonds of specified financial institutions within six months from the date of sale of the existing property These bonds have a tenure of five years and interest received on these bonds is fully taxable. You can plan to repay the home loan after the completion of the five-year tenure of the bond