Reconsiderations are very rarely considered for TRVs and are only done based on what you submitted. You cannot ask for reconsideration and shorten the trip - or add additional evidence. I don't see reconsideration succeeding since the trip you asked for was too long and IRCC likely sees this as demonstrating a lack of ties to their home country. Having said that, if you want to submit a case specific inquiry and try, you can certainly do that. Given global events, it might be several months before you have an answer.I see.. so there is no way I can request for reconsider/ appeal
You can appeal but only to the Federal Court. This will take many months and cost you thousands of dollars (you will need to hire a lawyer). I'm not sure on what basis you would be appealing. I think IRCC has strong grounds to say the application was correctly refused based on the request for a six month visit.
Your best option is to reapply from scratch and put together a stronger application.