what remedy is available if any SDM is not delivering any order within one year

You have mentioned RoR and Talathi, local connotations, which require research work to understand facts posted and oblige, it is better to use proper terms used Indian verson, if not universally used terms.

If SDM did not pass any order on appeal, you have the only option to request / expedite him / her and / or file a writ petition under Article 227 of the Constitution of India through a local prudent lawyer.

As rightly suggested by expert Dr Vashistha Sir, you may file a writ petition seeking direction for an expeditious trial.

But remember that this type of delays are common in the execution courts, hence you personally follow it up regularly and frequently.