Sources said Kumar, who is travelling to India en route to Canada, will soon reach his country, and left Houston on "voluntary departure".
Without confirming his Canada visit, Kumar's lawyer, Roger Jain told PTI that the filmmaker is out of Houston and the United States for now.
Kumar's departure marks an end to the tumultuous few weeks for him during which he was arrested and jailed for over 20 days.
Pradip Parekh, a spokesman for the Hindu Congress of America, which invited Kumar to the US, said Kumar wanted to go home and out of the country as soon as possible.
"It's so outrageous, and hard to swallow that the Indian government didn't do much to secure his freedom earlier, despite the fact that it promises in the Indian passport that it will take care of its citizens in any country," he said.
He hoped that appropriate action would be taken to ensure that such an event did not occur again with innocent Indian citizens in the future in any foreign land.
Kumar was convicted of illegally carrying brass knuckles in his checked-in airport baggage.
He pleaded "no contest" to a misdemeanour weapons charge in exchange for time served so he could return to India soon.
Kumar was sentenced to 20 days in jail and given credit for time served.
The 40-year-old resident of Malad in northern Mumbai was detained bny Houston airport security on August 20 after he was allegedly noticed acting suspiciously and Islamic "fundamentalist" literature was found in his carry-on bag.
He had been invited to Houston to participate in a Hindu organisation's conference. The literature was said to be used to educate the participants on the recruiting techniques of 'jihadists'.
A search of Kumar's checked-in baggage also found brass knuckles, which are illegal in Texas.
Although the item can be carried in stowed luggage, according to the Transport Security Administration, it's against Texas state law to possess them.
That landed Kumar in county jail where his passport was taken from him, and in Immigrations and Customs Enforcement detention for failure to have a passport.
After he made bail for the state charge on August 23, federal authorities revoked his visa and detained him, without bail.