It is the Indian Space Research Organisation's first mission to land on any celestial body and a follow-up to Chandrayaan-1 launched in 2008.
The first mission had the credit for discovery of water on the lunar surface.
The objective of the mission is to take up a detailed study on understanding of the origin and evolution of the Moon, according to ISRO.
"All preparations for Chandrayaan-2 are going on for the launch scheduled at 2.51 am on July 15 from Sriharikota," Sivan told reporters after offering prayers at the Lord Venkateswara hill shrine at Tirumala, on Saturday.
ISRO had earlier said all three modules of the moon mission - Orbiter, Lander (Vikram) and Rover (Pragyan) - were getting ready for the launch and the lander was expected to touch down on the lunar surface in early September.
In a brief interaction, Sivan, also the Secretary, Department of Space, said the lander would make a soft landing in the lunar South Pole, an uncharted territory so far, on September 6.
He ruled out rains posing a threat to the launch. "There will be no effect since the launch vehicle (GSLVMkIII) is rain protected," he told reporters amid a downpour here.
The Chandrayaan-2 would be carried by the GSLVMkIII, dubbed 'Fat Boy' by Indian scientists for its ability to carry satellites weighing upto 4-tonnes.
Asked about the total mission cost of Chandrayaan-2, Sivan said it was Rs 1,000 Crore.
Chandrayaan-2 is an advanced version of the previous Chandrayaan-1 mission which had 11 payloads - five from India, three from Europe, two from the US and one from Bulgaria.
(With inputs from PTI)