Renesmee and Jacob will have a relationship as soon as Renesmee is fully grown. How will their relationship work with the fact that Renesmee will never age further and live forever but Jacob will grow old and die since he is a werewolf?

As a werewolf, Jacob also has the capacity to stop himself from ageing. वेयरवोल्फ don't age while they're still shifting, so all he'd have to do is keep going into भेड़िया form regularly. The other वेयरवोल्फ just eventually chose to stop in order to age with their families, फ्रेंड्स and imprintees/partners.

Technically, Jacob can choose when he wants to stop being a werewolf and will then start aging again. But I don't think he ever will so that he can have his true प्यार with him forever.