The best way to approach this problem is simple yet tricky sometimes.
You first need to compress the folder into a zipped file and upload the same into your google drive.
While doing so, Make sure that the folder is in the root directory of the drive and not in any other subfolder!. If the compressed folder/data is in other subfolder, you can easily move the same into the root directory.
Compresses folder/data in another subfolder often messes with the unzipping process when you will be specifying the file location.
Once you did the afore mentioned tasks, enter the following commands in the colab to mount your drive:
from google.colab import drive
drive.mount('/content/gdrive')
This will ask for an access token that can be generated by clicking on the url displayed in the output of the same cell
!ls gdrive/MyDrive
Check the contents of the drive by executing the above command and ensure that your folder/data is displayed in the output.
!unzip gdrive/MyDrive/<File_name_without_space>.zip
eg:
!unzip gdrive/MyDrive/data_folder.zip
Executing the same will start unzipping your folder into the memory.
Congrats! You have successfully uploaded your folder/data into the colab.