Questions & Answers about El regal que tinc és per a la mare.
Here, que is a relative pronoun, meaning that or which in English.
So:
- El regal que tinc = The gift that I have
It connects el regal with the clause tinc.
Catalan often uses que in the same kind of way English uses that:
- La noia que conec = The girl that I know
- El llibre que llegeixo = The book that I’m reading
In this sentence, que is necessary. You would not normally leave it out the way English sometimes does.