Results for nearly half of the 70 constituencies have been declared as per reports around 6pm, while counting of votes on other seats are underway.
A total of over 1,200 rounds of counting are scheduled to take place for the entire exercise.
Minimum rounds were held for Delhi Cantonment constituency (10), officials said.
In Okhla, 26 rounds were held, while for Vikaspuri, Badarpur, Karawal Nagar seats, a total of 27 rounds are to be held, senior officials in the Delhi Chief Electoral Officer's Office said.
However, the rounds are likely to go till 35 on some seats, they said.
AAP's sitting MLA Amanatullah Khan won from Okhla constituency by a whopping margin of over 70,000 votes.
Delhi CEO Ranbir Singh said, the exercise will take very long as VVPATs are to be matched too.
"Entire exercise is being conducted as per the procedures laid down by the Election Commission. Ensuring accuracy is our top priority, so counting will take time, and people would have to be patient," he told PTI.
For some constituencies, where the counting rounds go beyond 30, the exercise can go on till late night, he said.
Counting of votes began at 8 am amid tight security at various centres set up across the national capital.
Exit polls on Saturday predicted a big win for the ruling AAP, which is now set to emerge victorious with a massive mandate.
Elections to the 70-member Delhi Assembly was held on Saturday and the final voter turnout was 62.59 per cent.
The postal ballots were counted first, till around 8:30 AM, and then the votes cast through EVMs are being counted, the senior official said.
"The counting centres are spread across 21 locations, spanning the 70 constituencies. Each centre has several counting halls, equal to the number of constituencies falling in that district," he said.
Each EVM consists of a ballot unit (BU), a controls units (CU) and a voter-verifiable paper audit trail (VVPAT.)
After counting of votes through CUs, from every assembly constituency, five VVPATs will be randomly selected and they will be counted, he said.
The counting centres are located across the 11 districts, including at CWG Sports Complex in East Delhi, NSIT Dwarka in West Delhi, Meerabai Institute of Technology and G B Pant Institute of Technology in Southeast Delhi, Sir CV Raman ITI, Dheerpur in Central Delhi, and Rajiv Gandhi Stadium in Bawana in North Delhi.