The rules are different for Qatar Silver and Qatar Gold, where the latter gets you Oneworld Sapphire status. This typically opens most of the Oneworld lounges that are used by business class passengers in the alliance with some caveats. In Doha itself status alone only allows access to the Gold lounges and not the business class lounges. Qatar's premium lounges in outstations, such as in CDG, are only available to business class passengers. Some alliance lounges are also subject to similar rules. Typically under these circumstances and where there are no other Oneworld alliance airline lounges, Qatar typically (but not always) has an arrangement with a contract lounge that provides those with QRPC Gold, access.
QRPC Silver or Oneworld Ruby, by alliance rules has no access to any of the Oneworld lounges. In Doha there is a dedicated silver lounge. Elsewhere it depends whether Qatar has contracted with a lounge to give their silver members access.
This search tool can give you some insight. But it is not up to date and can be somewhat glitchy, where at times it simply does not work.
https://www.qatarairways.com/en-us/l...worldwide.html