<this line edited cuz Collective clarified, ty!> - Perhaps it would be better to email Khaled
for permission first, though it may take several days or longer to receive a reply (if not replied to here). TBH, I don't think he'd mind, if you uploaded an infected client and claimed it was mIRC, perhaps a different story!
Alternatively, there is certainly nothing wrong with linking to the official mIRC download page
, or for a direct download, finding out the link for one of the mirrors and providing a link to that. Bearing in mind if people are from all over the world not all mirrors will work best for them.
If you choose the former option, I'd suggest you make sure the latest version of mIRC, 6.14, is the version available.