Captial gains

As per u/s 54 of Income tax Act, provide us the locking period of 3 Years, in which assessee can't sale the reinvested property otherwise the LTCG will be reduce from the cost of property which is sold by assessee. 

in this case , he bought a house includes commercial shop too. my question is re-investing must be only in residential house or both (commercial complex, shop., etc.,)?

Genuine hardship means situation wich is out of our control, like natural calamity etc than in that case deptt. can condone the contravention provision of act.