An Interpol red notice is simply a notification to member countries that the requesting country has made a request for extradition/arrest. It’s not an international arrest warrant, and that’s why Canada did not act upon it.
‘Khalistani terrorism’ is a complete myth. There was an insurgency decades ago in Punjab but you will find 0 instances of violence or terrorism associated with Khalistani activism in the contemporary world. Certainly nothing around ‘Khalistani Tiger Force’ - which I’ve never heard of and is most likely an Indian propaganda construct.
Nijjar himself was actually involved in peaceful, diplomatic arrangements including the arrangement of a referendum in Canada. Calling him a terrorist is like calling those asking for Scottish independence terrorists.
Oh please, he was wanted in wanted in several cases, including the 2007 blast that killed six and injured around 40 people in Ludhiana, Punjab. He was also involved in the assassination of Rashtriya Sikh Sangat President Rulda Singh in Patiala in 2009. Canadian local authorities placed him under house arrest on suspicion of terror activities - hardly the act of peaceful separatist.
Just today a congress block president was murdered in his home. Below is the video of that murder being captured in CCTV, if you want to watch.
https://x.com/thind_akashdeep/status/1703791107946263033?s=61Hours later, a gangster and a designated terrorist, Arshdeep Singh Gill, took responsibility for the murder in a Facebook post purportedly from his account. He is currently a permanent resident of Canada. So while mass killings might not be done, targeted killings for personal or business gains are done by people associated with Khalistani movement.
As for the red letter notice, they aren’t issued just because a country is requesting it. As per their own website “All Red Notice requests are reviewed for compliance with INTERPOL’s Rules by our Notices and Diffusions Task Force, a specialized multilingual and multidisciplinary task force comprising lawyers, police officers and operational specialists.”