Car Parking dispute in Flat

I have booked an apartment together with a garage in Serampore, West Bengal. about 75% of the money was paid by me. They signed an agreement. In this agreement, they did not mention parking area details. They took about 3 lacs for parking space but did not mention how many square feet were reserved for this. In this agreement, they mentioned “Parking for one car”. My question is, when I am going to sign a sale deed, they have to say how much space they allow to be used as a garage. please expose on this issue what legal action should be taken against this.