Withdrawn currency worth 23K Crore

I have read in newspapers, the withdrawn currency (500 and 1000 rupee note) is equivalent to 23K Crore Indian rupees. Obviously Government is to substitute it with new currency. But it's sure, 23K crore is not to return back to banks and government. Fearing income tax procedures, many are destroying notes and a good amount might be invested in foreign banks (I don't know if money equivalent to that dead money in Swizz is circulating in Indian markets, and how it's calculated). 

If so, how is Government going to fill that gap? Will those destroyed money be lost forever? Or any other provisions available as per Indian law to allow Indian government to print those notes and circulate (equivalent to that lost money value). My question may be a big blunder, yet I want to know, What's next????