I had to remove a toilet because I had to repair a piece of ceramic floor tile. When I put it back, I cinched down the toilet bolts and one kept on tightening by did not get tight. I took it off and saw that one of the slots was rusted out. I tried to unscrew the toilet flange ring and the screws were rusted on so I took an angle grinder and ground the heads off and cut the ring off. I replaced it with a ring that is in two parts or halves. To get the old one off, I had to pull out some of the old screws after the heads were off or pound the screws in further. I used the same size screws as replacements but most of the holes were larger so the screws would not tighten or hold anything. I tried using Durham's Water Putty to put in the holes . I mixed pu the powder with the water in the kitchen and had a nice paste. By the time, I got to the bathroom, which was 30 seconds away, the putty was already starting to set and got somewhat crumbly. I tried to stick it into the holes with both a stick and a coat hanger end, and it helped a little bit.but I had to work fast because it was setting up more and this was no more than 2 minutes after I made the paste. The directions say it starts to set up in 5 min. I set the toilet on.and started tightening up the toilet bolt. One got snug and the other did not get tight. Maybe I did not tighten it enough but I suspect I did tighten it enough. My suspicion is that the tightening may have caused the screws to come out that were holding the ring on. At this point I decided to ask the forum. I did not turn the water for the toilet back on.My questions are: What should I do now? Tighten up the bolt to see if it gets snug? Take the toilet off and check the screws? If the screws are loose, how can I get them to seat firmly? If most woodworking projects, I would jam splinters of wood into the holes to tighten up the screws but there are six screws holding the ring on. Any suggestions? Thanks.

just to be clear.
the toilet bowl can not be snugged down because the flange replacement ring (stainless i hope) can not be secured to the finish floor well enough?
now you are trying to make the holes in the floor strong enough so screws (stainless i hope) can be snugged securely ?
you mentioned sticking bits of wood into the holes.
i do something similar but i use cut off bits of plastic tie wraps.
cut them up. cram the hole full leaving them sticking up a little and tighten away.
plastic will never rot and stainless is forever.

Screwing a repair ring down to the floor is NOT the way to replace a flange. You will probably get leakage from the toilet with this repair. How are you going to seal the halves of the repair ring to the pipe, not the floor?
You also didn't say what material you're working with (PVC, cast iron ?) From what you said about cutting off the flange, I imagine you're working with pvc. The proper repair involves cutting the pvc riser and replacing the riser and flange. I would recommend a pvc flange with stainless steel rim with stainless steel wood screws securing the flange to the floor.