Traveling to Canada on expired passport, valid visa

[canuck78]

Yes, I have applied for work permit extension Oct 2025. Since I am planning to travel
To India on Jan 2026. Will I get re entry in Canada with my existing work permit (validity sept 2026). Applied for extension will cancel my previous valid work permit?

You need to apply for a TRV as well before it expires. A WP is not a travel document.