what are the signs that the fig tree is very thirsty and what are the signs if it's over watered ?

Thirsty, if in pots, pot is very light in weight, droopy leaves, lethargic

Over watered: pots are overly heavy, soggy, yellowing leaves.

I noticed that leaves curling up means too much water for my figs (no root rot yet).
Wilting leaves diagnosis depends on the previous watering history. Too wet -> root rot, too dry -> thirsty. 

Do I water once a day for in ground and potted ?

I am watering once every 3 days based on the weight of the cups (this is for cuttings). I even use a scale to do that ("fig fever is to blame for that" :))
I up potted some cuttings to 1 gallon container and my intention is to do the same. I keep them in the house though, I'll see when I'll moved them outside.

in ground trees are different. i think first season, you water it on regular base depends on the way the tree is reacting. then slow it down next year and so on. by 4th year or so unless it's extreme draught, you shouldn't really have to water them. or at least that's what i heard. do base your schedule on what i'm saying. i don't have fig trees in ground. herman or some other members who are trailing the fig trees in northeast might have better idea. they grow them in ground.

If overwatered I have taken a chop stick and punched it through the soil 5-6 times to get some air in there for the root system as well as to help drain it. Also tipping pot 45 degrees will help drain a soggy pot. Hope this helps.