"I have some advise for you"

There is a spelling error "Advice" is the noun "Advise" is the verb. Apart from that the English is correct.

Is it "condescending" depends on the context. Are you in a position in which advice is expected? If you are not sure whether advice is welcome, you can always ask

Would you like some advice?

or

I've some advice for you, if you'd like to hear it.

There's always a dialogue and a social context.