Tax matter

I have 1 question here. If malaysian citizen been seconded to oman from malaysia company, is they being tax by the malaysia company if their salary being paid by the malaysia company remitted to their local malaysia bank?

You need to check the tax laws of your country.

For most countries, it is based on residency i.e. if you stay outside for a certain period of time, you are classified as a non-resident for tax purposes and either pay no tax or a reduced rate of tax.  This has nothing to do with receiving money in your local bank account.

However, for some countries, receipt of funds in local bank account means that the income was derived in home country which leads to tax incidence.

And also, secondments such as the one you describe, for multinational companies, come with tax equalization programs.

As I said, you need to get in touch with a tax professional in your home country to be able to get the right guidance.