Please Help& - Is This An Ancient Byzantine Silver Coin Or A Modern Fake?

Yes, they glued the fallen-off pieces back onto the coin, and the restoration is very shoddy. Do you think this coin is genuine?

I think it is genuine as well. That would be some elaborate fake to make such a thing and glue it that way. When I have a delicate coin like that with a break I carefully fit a case around it, and let it sit static in such a way it can't separate the two parts. Like a slab case with that foam plastic insert I cut with a razor to fit the coin dimensions. Then when I seal the case with the info I write, don't take out of the case as it is separated along what looks like a crack in the coin in the case. That glue work is just never going to work well. And I never understand, that if someone were going to try such a glue, why not just get a fine tip soldering iron and hard silver wire solder? They plan on making something to last forever in a collection, then take the time and try that perhaps. But not that glue.

Thanks ! I do more research and found this might be made by Mstislav Volodimirovich the Brave, which Imitated a Constantinople mint Miliresion of Basil II Bulgaroktonos.

Here are pictures of the imitation that I found. It looks more "blurry", but as an imitation, I think it is well made.

I agree, and it shares with yours the weak planchet that resulted in cracks.
But it has mistakes in the legend on the reverse that are not present on yours:
Line 1 - BAISL ibstead of BASIL.
Line 3 - (II) ORFARS instead of II ORFVROS
etc.

For a coin in better condition, the weight could also be indicative, but yours is missing some metal, and possibly was clipped since the obverse legend is so close to the edge of the coin, so I don;t think weight will help.

I think the miliaresion of the 10th century was made of good silver, so if you were able to have the silver content assessed by analysis (for example, by a jeweler or coin dealer), this might help confirm.