Can you put a SD or mini SD or micro SD in the iPad mini 4 ?

There is no way to install an SD card into an iDevice.

The only way to get more internal storage on an iDevice is to purchase a larger internal capacity iDevice.

If you need more storage on your iPad, you can either backup your data by connecting up to a computer running iTunes and if yoo use a Mac,msave photos to iPhoto/Photos App.

Then, once you backed up, you can disconnect your iPad and start deleting data of the iPad to reclaim some free storage space.

Another method is to store all your data to a cloud sevice (offsite server storage) like iCloud or a a service like DropBox and then delete data off of your iPad to make additonal storage space.

Yet another method is to get a wireless, WiFi enabled portable external hard drive from Seagate or Western Digital or WiFi enabled USB flash drive from SanDisk which gives you a pocket size local storage device to transfer your iPad data to these drives via local, built-in WiFi transmitter/hot spot.

Good Luck.

No.