Das, 57, who is currently Fertiliser Secretary, would assume charge by Monday or Tuesday, a top official said.
Takru, 59, who has been Revenue Secretary since March, has been appointed Secretary to the Department of North Eastern Region (DONER), an official order said.
Das was appointed as Fertiliser Secretary on December 26 last year. Prior to that, he was Special Secretary at Department of Economic Affairs in the Ministry of Finance.
This is the first major top bureaucratic change in the Finance Ministry since Narendra Modi government came to power three weeks ago.
The Finance Ministry, which is currently preparing Modi government’s first budget, has Arvind Mayaram as Finance Secretary, R P Wattal as Expenditure Secretary, Ravi Mathur as Disinvestment Secretary and G S Sandhu as Financial Services Secretary.