I just want to know Is there a way in Testcomplete to efficiently compare two test log files?

That's not possible inside TestComplete at this time but you can add a Feature Request here

https://community.smartbear.com/t5/TestComplete-Feature-Requests/idb-p/TestXCompleteFeatureRequests

I have used a tool called Beyond Compare for line by line document comparing and you may find that helpful to use with the exported files.