Bhai for 1.3 gli you will need 75w90 api gl4 or 5 gear oil, around 2 liters i suppose. Please check manual if you have one. This cannot set you back more than 2000 rs. Waise to mai zic dalwaleta hu apni gaariyo pe, but aisin will be a better option. And your mechanic is a fool if he says nai change karwna hota.