SVA763 (Saudi Arabian Airlines Boeing 747-100B) departed from Delhi International Airport to Dhahran at 18:35. KZA1907 (Kazakhstan Airlines Illyushin II-76) was descending to Delhi airport at the same time.Both flights were controlled by VK Dutta.KZA1907 was cleared to descend 15,000 feet altitude, whereas SVA763 was cleared to climb to 14,000feet. After 8 min, KZA1907 reported that they reached 15000 ft altitude, but they were descending to 14,500 ft at that time and were continuing the descent.