Option 1 states that the BrahMos missile has a flight range of up to 290 km. This is correct, as the BrahMos missile indeed has a maximum range of 290 km. This means that it can travel up to 290 km from its launch point, making it a highly versatile missile in terms of its reach.

Option 2 states that the BrahMos missile is capable of attaining a speed of 2.8 Mach. This is also correct. Mach is a unit of measurement used to determine an object`s speed relative to the speed of sound. 2.8 Mach indicates that the BrahMos missile can travel at 2.8 times the speed of sound, making it a supersonic missile.

Option 3 states that the cruising altitude of the BrahMos missile could be up to 30 km. This statement is incorrect. The BrahMos missile is a low-altitude cruise missile that generally flies at a height of less than 10 meters from the ground, skimming along the terrain to avoid detection. It does not typically fly at altitudes as high as 30 km.

Therefore, the correct answer is option 1: 1 and 2.