What is the batter structure (R.C.C or steel)?

Steel is strong both in tension as well as compression when strength parameters are only taken steel is the best chice.But if we consider safety and economy to consideration R.C.C would be the best chice.Steel would be hazardous because of its conducting capacity of electricity,heat etc.

it depens on the type of the structure...

in case of residential of office buildings i think steel structure is better.......

1. seff weight is much lower than RCC. so it has low foundation construction cost;
2. less self weight gives better seismic resistance.
3. the whole construction process consume very much less time than RCC construction.
4. steel is more durable and recycleable . so salvage value is high.