In CCS University, to pass a subject, you must get at least 40% marks by adding your internal and external marks together. You also need to score at least 50% in total for the semester to move to the next year.

In Digital Electronics, you got 28 internal and 22 external. So your total is 50 out of 100. This means you passed the subject based on total marks.

But your result shows failed. This may happen for a few reasons:

Maybe you missed too many classes, and attendance was low.
Some departments want students to pass both internal and external separately.
Or there could be a mistake in the result.

You should visit your college exam office or department and show them your marks. Ask them why it shows failed. If it’s an error, they can help correct it. If needed, you may have to give only the external exam again.

You can read the CCSU rules here:
https://scriet.ccsuniversity.ac.in/updates/20201026_BBAOrdinance2020onwards.pdf
https://www.ccsuniversity.ac.in/ccsu/

In CCS University, to pass a subject, you must get at least 33% marks in both internal and external exams separately. Your marks in Maths II are 29 internal and 23 external, which is fine because your external is above 25 out of 75. So you passed Maths II.

In Digital Electronics, you got 28 internal and 22 external. Even though your total is 50, your external exam marks are only 22, which is less than 25. That is why the result shows failed in Digital Electronics. You did not get the minimum passing marks in the external (theory) exam.

Now you will need to give the external exam of Digital Electronics again in the next back-paper exam. You only need to improve your external marks to at least 25 out of 75 to pass.

You can check the CCSU exam rules here:
https://filesccsu.blr1.cdn.digitaloceanspaces.com/public/pdf/ccsum/All-PDF/2020-01-17_787.pdf
https://ccsuniversity.ac.in/ccsu/