Dear blackArmada_DXB,
I understand what you said and i don't mind you asking me so many questions as you intend to help as precisely as possible in a meaningful way, than others. It seems you have very good technical knowledge on Cars and Nissan as such. Its really nice to have person like you present who can help discussing the problems.
Actually when this problem started i was away and my wife was occasionally driving the car. On my return i did exactly what you said and drove the car to my mechanic and made sure all the fluids, oil, coolant and everything is topped up and in good health. My mechanic advise me that it looks like transmission is getting bad, only alternate is to rebuild it (close to 3k) or buy used one at same price of 2.5k to 3.5k dirhams.
May be i should get the whole transmission oil flush with Royal Purple Max ATF as you advised and see if it helps, before diving in for rebuild or refurbish transmission. Any idea where i can buy this Royal Purple Max ATF in Dubai?
Thanks for wonderful explanation and all the help.