Dear Sri Sitaraman,
In general, for any tender plants, watering should be copious, and once daily. Water logging should not be and soil should be with required humidity ( not wet ).
In general there is no thumb rule to give certain quantity of water per plant per day. It mostly depends on the type of soil. Some plants will be of more water loving and some will not be. Pomegranate plant is a semi Arid zone plant and it rquires only humid soil, but not wet and/or water logging. The season( summer, rainy, winter ) also plays a vital role in watering quantity.
Daily ,for couple of days, give say 500 ml of water, per 2 months old pomegranate plant , and observe soil near the plant after 4 hrs, after 8 hrs,next day morning. If the soil abutting to the plant is humid,watering is sufficient. If the soil is dry, increase water giving to 750 ml, or little more.
On study, you will know, how much water is to be given daily once.
with best wishes, g.p.rao, farmer