In Geneva, is it easy to get a job there in Software Engineering if I know French? And English?

Having both French and English is a good start but there are more factors to take into consideration, depends on your skill set, current market conditions, etc etc... contact a few agencies and get feedback from them?

Do you know any good agencies in Geneva for IT jobs? Can easily see some lousy agencies just do business by reusing the same ads on internet from the original companies.

It is always better to apply direct first to companies if they are advertising on their website, its a huge cost save for them.
Some companies have preferred suppliers, so the 'lousy agencies' you refer to may be on those lists, but perhaps they are not. My original point to the OP was to get feedback/market information from the agencies since they have their heads in hiring IT staff all day everyday and will be able to give advice on how easy it is to get a job in Geneva.