Hello. I am paying for 50g icloud but my phone memory is still occupied. What do i have to do to freeup storage space o my phone

iCloud mirrors what is on your phone; it isn’t a way to move stuff off your phone, because it syncs all additions, deletions and changes. The purpose of iCloud is to sync multiple devices, so if you have, say, an iPhone, an iPad and a computer it will assure that exactly the same content is on all of the devices.

If you want to free up space on your phone you need to use an archiving service such as Google Photos, Dropbox, box.com, Microsoft Onedrive, etc, to move stuff off your phone (which also moves it out of iCloud).

See the "Content categories" section in:

How to check the storage on your iPhone, iPad, and iPod touch - Apple Support

The "Other" category are non-removable mobile assets, like Siri voices, fonts, dictionaries, non-removable logs and caches, Spotlight index, and system data, such as Keychain and CloudKit Database. Cached files can't be deleted by the system.

A very large "Other" (greater than about 10 GB) is usually an indication that something is corrupt. About all you can do is restore the iPhone from a backup or even more drastically restore it as new (which loses all your data).

Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

Restore your iPhone, iPad, or iPod to factory settings - Apple Support

iCloud storage will not resolve the problem. You need to actually delete content from the phone. If it is content you want to preserve you need a non-Apple archiving service to move it to. Or replace the phone with a new one with more storage.

First action is --> Manage your photo and video storage - Apple Support

iCloud storage is independent of iPhone storage. To get more space on your phone, you need to delete something.

Just install the Google Photos app on your phone and it will automatically copy all of your photos.

Have you tried optimising storage through iCloud. That will save lots of space on iPhone.

Store your photos and videos in iCloud

Your photos and videos are stored on your device in their original, high-resolution version. This means that they use a lot of space on your iPhone, iPad, and iPod touch. With iCloud Photos, you can make more space available on your device and have your entire collection, everywhere you go.

Get started with iCloud Photos:

1. Tap Settings > [your name] > iCloud > Photos.
2. Turn on iCloud Photos.
3. Select Optimize iPhone Storage to save space on your device.
4. 

With Optimize Storage, smaller, space-saving photos and videos are kept on your device while all of your original, full-resolution versions are stored in iCloud. And as long as you have enough space in iCloud, you can store as many photos and videos as you want.