A non-resident indian returns after 25years for settlement, when his tax liability begins or any tax holiday?

is it true that a returned Non-Resident Indian will be on 'not ordinary resident' status for 7 years after his return and he would be exempted from paying any tax or filing any tax returns during these years and would be essed for tax only after these 7 years? or else when his tax liability begins & what are the liabilities and tax slab if he is over sixty years of age.