I have S3 Neo GT-I9300I Jelly Bean 4.3. PDA I9300IXXUAND1 CSC I9300IOJVAND1.
Its not rooted.
I want to upgrade to KitKat 4.4.4 and I searched and found This Rom:
First: Is that suitable for my mobile?
Second: what I do if I wanna downgrade again to Jelly Bean 4.3? (I downlowded and installed the Rom of PDA I9300IXXUAND1 CSC I9300IOJVAND1 previously with Odine 3.10 and the mobile is still in warranty period. I can update till now.
Thanx in advance
The ROM seems to be okay judging by the name (right phone and same region code) so no problem there, assuming you were looking for a ROM for one of the following : Austria, Belgium, France, Germany, Hungary, Italy, Nordic, Spain, United Kingdom.
You should be able to downgrade to 4.3 without a hitch as long as you take a compatible ROM (do not mix up i9300, i9300I and i9301I) with the right region code (else your phone could have network or language issues from what I've heard). You may have compatibility issues with some apps though.
DO NOT TRY TO DOWNGRADE BELOW 4.3 ! It would probably brick your phone because of knox (unless I'm wrong about it being on the i9300I).