Is it safe to take syntocinon if I give birth at home?

No. Oxytocin should be delivered only in a hospital setting where your baby can be monitored for distress and an emergency c-section can be accomplished in an expeditious fashion. The preferred administration is intravenous, as that can be discontinued rapidly. At home, you only have the nasal spray, and the effects go away much more slowly.
No. If you need it you should be in a hospital setting. Do not trust anyone who promises to give it to you at home.