Hi, I know it's too late for Mohammad, but maybe interesting for others:
Oman is a very pleasant country, very safe, friendly people, excellent food, safe potable water , even no problems for women in bike shorts.
Bring a small tent, because there are no hotels off the beaten track.
Camping is everywhere possible and safe.
The good news for roadbikers is, that almost all roads are currently being paved, which is bad news for mountainbikers, because in a few years there will be no dirt roads left.
Temperatures in March were quite high. 34° C at 9.30 am in Muscat, well over 40° in the interior parts of the country.
Unfortunately the sea almost everywhere was full of jellyfish.
Norbert