Thankyou for such a detailed reply. Yes you are right. I have contacted parts central and they deal only in foglamps so I need to arrange foglamps and cover from somewhere else.
Now I am confused
1. whether to buy stock LED fog lamps of revo for altis 1.6
2. go with grande genuine foglamps and later on installing photum h11?
If I go with no 1 option, am not sure whether revo LED foglamps would adjust in foglamps cover of grande coz I think there size is big and housing for foglamps in grande cover are small. Not sure though. This is the picture of revo and fortuner LEDs and grande foglamp cover.

Grande OEM foglamps
Grande foglamp cover
LED foglamps type 1
LED foglamps type 2