The 'normal' tax rate is, 20%, with a higher rate of 25% on annual incomes in excess of EGP10,000,000 (should you be so fortunate), and also with lower rate bands for relatively small bands of income.
If (broadly) you are physically present in Egypt for less than 183 days, a flat rate of 10% applies instead.
For more detail, see the English language version of the Income Tax Law (and especially Articles 6 to 16)
If you are a resident of a country which has a double tax treaty with Egypt, and you are present in Egypt for less than 183 days per year, and you are paid from outside Egypt, the treaty may provide that you are exempt from tax in Egypt.
The above is broad summary. The actual position will depend on your specific circumstances, and you should of course get detailed advice from your prospective employer and/or a suitable tax advisor.