What can I take instead of this tedizolid phosphate 200mg tablet if it isn't available?

This is a specific antibiotic usually reserved for certain skin and soft tissue infections, and the right alternative really depends on the exact infection and bacteria involved. Swapping antibiotics on your own isn't advisable since the wrong choice could mean the infection doesn't clear properly. Please get in touch with the doctor who prescribed it - they can suggest a suitable alternative available near you.