which windows are better for goa wooden or aluminum sliding

While good quality wooden joinery (teak etc.) is appealing and conventional, it tends to be costly and requires termite treatment. There is additional cost of poishing/painting the framework afterwards.

Aluminium is increasingly being used in commercial buildings/factories/offices. Usually the sections are available by weight or by lengths. You can go for a raw section, anodised section or a powder coated one (colored). 

Starting range of wood and aluminium would cost you around the same.