Talaq will take place on the same day on which the husband wrote talaq to his wife through Shariah Panchayat. As far as the matter of iddah is concerned if she had stayed after nikah with her husband then the iddah of talaq shall be counted from the day when talaq was written and it shall be over after completing three haiz (menstruation cycle). But if the woman did not meet her husband in privacy after nikah then there is no iddah for such woman.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband