Khan retired as RBI deputy governor in July this year after serving for nearly four decades.
"As India experiences a rapidly-evolving financial services landscape, his appointment underscores KPMG in the country's strategic initiatives and effectively steers the firm toward leadership position in this domain," KPMG India CEO Richard Rekhy said in a statement.
During his tenure at RBI, Khan spearheaded projects relating to macroeconomic policies, regulation and development of financial markets, debt management of the central and state governments, financial inclusion, microfinance and rural credit, payment and settlement systems and the Foreign Exchange Management Act (FEMA).