A small correction not top 5 richest men, 9 536 743 Trillion will be his bank acc after one year.
Assuming he works only 10 months and take 2 months vacation, the projections are 25 lac^10 = 9 536 743 164 062 500 000 INR
To get the scale US GDP is 16.8 Trillion on 2013, even if you adjust silly dollar to INR conversions he should be buying entire US 1000 times over just from his pocket money!
but there is only one very very crucial problem at this point:
http://www.wolframalpha.com/input/?i=gdp+of+earth
world GDP is 74.9 Trillion INR.
Who can be on the other side of his buy order!!!?