Members from the board have been so kind and patient to help me answer the question .... though the effectiveness of the plant in the garden didn't seem too positive but I'm not giving up!
So far I understand ..... Pelargonium citronella (also know as the Mosquito plant) has some effects provided the plant must be shaken by the winds to distribute the citronelle fragrance and also a plant that looks like the lemon grass .... Citronella also know as Cymbopogon nardus.
Here are the pics of the two plants .....
This is the Pelargonium citronella also know as Mosquito Plant.
Once I get hold of the plants, I'll show you where I planted them LOL