Tu m'avais promis que tu viendrais au restaurant pour que je puisse te présenter Noémie, ma nouvelle copine

Bonjout Tuhin,

This is a bit tricky!

Le Subjonctif Passé is used if the action had to be completed before the action of the main clause: you promised so that I would already have been able to introduce Noémie. This would sound strange here.

Instead, Le Subjonctif Présent is used to emphasise that introducing Noémie was supposed to happen at the same time as meeting at the restaurant.

Concordances des temps

I hope this is helpful.

Bonne journée !