Can an online english speaking course help me become fluent in english?

Definitely, it's one of the several options to acquire fluency in English.

Sure it can as a subsidiary tool 

Of course It can help but that alone is not sufficient. You must try to read loudly ,write regulalry.  One method I found very effective among adult learners are  reading the newspaper regularly and recording them and their listening to them on a regular basis. 

Sure it will improve your speaking language to an extent but it still not like the actual or real life contact. It is still a good idea if you choose a good course from a respectful language institute. 

Of course without any doubt

For sure it can help you alot

Of course, yes it can help a lot.

Yes, it does help people to learn the language.

Yeah,It's so good to chat with others,whom speaking English,especially the native speakers of English.This encourage you to search of new words,for example & not to be so commit with rules of the language.If you want, I am ready chating with you,any time you want.Thank you very much.

yes certainly  help you online speaking couarse 

yes but all depends on your readiness to make progess in speaking