How did Raghav Chadha become Delhi voter?

BJP MP Raghav Chadha's name, marked "permanently shifted" during SIR in Punjab, now appears in ECI's electoral database for Delhi's Rajinder Nagar. Delhi CEO's office said Chadha filed Form 6 for inclusion on August 26 and the ERO approved it on September 2. His name isn't on Delhi draft rolls published on August 31 but appears as 747th entry online.