What would be a fair method of dividing the ownership in the venture?

Mr Rajeshwar Thakur, B.Sc., is working as finance director in a large company at Lucknow. He has been working with the company since he passed out his MBA from IIM, Lucknow about two decades back and is currently earning Rs 12.00 lakhs per annum.
Mr Thakur spends every July with his family in a small town at Kichha, near Bareilly where he has his ancestral property and a big house. He rents the parental house every August for Rs 7,500 p.m. About a fortnight after his arrival at Kichha this July, Mr Thakur was approached by a neighbour Mr Chaman Gupta.
Mr Gupta was a permanent resident of Kichha, who had retired from the medical profession last year at the age of 58 years and owned 30 acres of underdeveloped land, at about 10 minutes drive from Kichha town.
Mr Gupta purchased this land in 1950 at a very low price. Similar underdeveloped land in the same area was available at Rs 10,000 per acre. Mr Gupta was getting bored with retirement and wanted to try his luck in a new venture. He wanted to develop his land into a retirement community with approximately 100 homes for senior citizens.