Can i use tamron 90-300 mm af macro on my minolta 404 si dynax ?

http://www.tamron-usa.com/assets/pdfs/272E.pdf
This is the manual for the Tamron SP AF 90mm
F/2.8 Di Macro 1:1 (Model 272E)

Tamron makes lenses with a variety of lens mounts. If the lens has a Minolta mount then yes, you may use it with your camera.

You may download a copy of the manual here.

The lens can be used on Sony's alpha-series digital SLRs.

change your VR unit

Mirror lenses have no aperture nor AF, so they mount via a T mount. A $30 item that screws on the end of a mirror lens that fits your camera. A mirror lens has it's physical likes and dislikes against a glass 500mm. A glass 500mm will give a better image if you can stop down to F8 F16. Then you have shutter speeds to consider and those lenses are usually connected to the camera's contacts. So they can be specific to a single body. There are older Tamron lenses that take Adaptall mounts, they are old and hard to find. But they solved the multiple body problems for "auto" program lenses. None had AF, when AF camera around, we were back to individual lenses per body.

Your Minolta QTsi Maxxum takes a Konika Minolta AF lens. These lenses work on these Konika Minolta DSLR cameras:
DYNAX 5D / Maxxum 5D
DYNAX 7D / Maxxum 7D

There should be a switch just in front of the back of the lens marked "AF" and "M". Set it to M for manual focus, AF for autofocus.

Minolta Maxxum lenses fit certain Sony digital cameras. Check this site as it depends on the specific model.

https://feltmagnet.com/photography/Digital-SLR-Cameras-and-Those-Film-Era-Lenses