for what angle of projections of two projectiles their ranges and max heights are equal ?

30 AND 60 DEGREE

Maximum height depends on the vertical component of velocity of thrown projectile, although it is not independent of thrown angle but at a certain velocity no two angles can have same Maximum height. 

In case of Max. Range the angles are θ and (90-θ)

FOR RANGE TO BE SAME SIN 2X MUST BE SAME

FOR HEIGHT TO BE SAME SIN²X MUST BE SAME

THUS THERE IS A SINGLE ANGLE

Angle α and 90-α.......

see vishal

maximum height may or may not be same as it depends on vertical componenet of the velocity but , for range,

theta=(90-theta)