The law of the place of enforcement. In Myanmar, this will be the Limitation Act 1908.
Article 117 of the First Schedule of the Limitation Act 1908 provides that a suit must be filed within 6 years from the date of the foreign judgment.
Not expressly stipulated under the Limitation Act 1908. The Arbitration Law 2016 provides for foreign awards to be enforced under the Civil Procedure Court in the same manner as if it were a decree of the court. In that regard, it may be likely that the suit must be filed within 6 years from the date of the foreign arbitral award.