Why the room temperature is more then the temperature of out side in a summer session

The indoor temperature can be higher than outside if the sun heats the walls of the building. Also, if you're measuring temperatures after the sun has set, a building will retain heat while the outdoor temperature falls.

In sum, the temperature indoors depends a lot on the amount of heat the building absorbs from the sun and the insulation values of the walls and roof.

You must be speaking of a room with windows, esp. ones facing generally south (here in U.S.). I have two separate living spaces. One is heavily shaded by trees and tends to remain cooler than outside. The other has little shade and many windows, it gets like an oven in the summer. Direct sunlight, esp. thru windows causes more greenhouse effect. (walls) prevent air circulation which could otherwise help cool the place. Finally, objects (such as houses) absorb more heat energy.
AIR does not absorb heat as well, so objects radiate heat while the air just circulates but does not
radiate heat directly.

Lack of breeze, the insulated walls, the body heat we give off, its a number of things.