The sleuths conducted the tax evasion-related search operation at residential premises of Bishnoi, son of former Chief Minister the late Bhajan Lal, in Hisar, Mandi Adampur and Gurugram in Haryana as well as in New Delhi.
The I-T raiding teams also questioned family members and collected a large number of papers from the premises, sources said.
As the younger Bishnoi, who unsuccessfully contested the last Lok Sabha poll as a Congress candidate from Hisar, left his residence in a private car along with the I-T officials, a handful of party supporters gathered there and raised slogans against the government.
Police was deployed in strength outside his residence to prevent any untoward incidents.
The MLA's wife Renuka, herself a legislator from Hansi, was not present when the sleuths arrived at their Sector 15 residence in Hisar.
However, Bishnoi's mother Jasma Devi was reportedly present at the house and she is said to be suffering from hypertension following the income tax raids.
Reacting to the raids, Renuka Bishnoi said in a Facebook post that they have been engaged in "clean politics".
"There have been searches at our residence. We request the workers that they should not worry. We have been doing clean politics and will continue to do so", she wrote.
The Bishnoi couple had won their seats in the 2014 assembly elections as Haryana Janhit Congress candidates, but they merged their party with the Congress in 2016.
( With inputs from IANS )