Do you have any fobs for the car?
On the 610 the key has the fob built in, you should have two keys with fobs in them unless one has been lost.
If you have a non working fob, it might they can fail due to battery, switch or solder, these can be fixed.
If you dont have a fob there used to be a kit 7701366232 that was shared between a number of Renaults that gave you a new roof transmitter and a matching key fob. I put one of these in my GTA. It is listed at 160 and may still be available, try your local Renault dealer or here:-
https://www.allcarpartsfast.co.uk/renau ... p-key-r19/.
I have a couple of spare blank keys to match these fob kits or can tell you where I got them.
There are two key fob designs out there. One is electronically programmed and I have no idea how to do this which is a shame as I have a few seond hand ones.. The other (older) design is programmed by soldering links and I can do this if you can find a second hand key of that type.
Ren Clio 19, 21 or 25 (and I guess espace 1) use these keys, but I had to buy a few before finding one so I could have two remote keys for my first 610.
Hope this helps.