why water is entering on the passenger side of truck when it rains?

First check to see if the sunroof drains are clogged--they can be checked / cleared quickly and easily by a shop blowing air through the drain. You can check if they are clogged by opening the roof and pouring a small amount of water from a cup onto the drain opening and seeing if the water is drained under the car or sits in the channel,indicating a clogged drain