Yes, Redmi 6 does have a fingerprint scanner. It also supports the face unlock.
Yes, Redmi 6 does have the LED notification light.
No. Redmi 6 does not have the IR blaster support.
Yes, Redmi 6 does have the portrait mode.
If your budget absolutely can’t exceed the Rs. 8,000 mark, go with the Redmi 6 without any concerns whatsoever.