I do understand that autocomplete/(tab to complete) can be disabled by toggling true/false in the settings file. But is there a shorter way to do it. Also, can we encode it for a particular folder/file?
I don't think you can accomplish this for a single file other than by manually toggling it. However, the sublime settings work on multiple hierarchical levels: General Settings < Syntax Settings < Project Settings. So if you want enable/disable a specific setting for all e.g. python files, you can open a python file and edit the settings in Preferences > Syntax Settings. If you want to enable/disable a specific setting for a project folder, open the project and add the setting via Project > Edit Project.