She threw the spear to a distance of 63.82m, a 58cm improvement over her own earlier national record of 63.24m set in Patiala in March last year.
The 29-year-old showed she has put behind the disappointment of the Tokyo Olympic Games by rewriting the national record for the eighth time since she first claimed it from Suman Devi in June 2014.
On Sunday night under floodlights at the JRD Tata Sports Complex, Annu Rani had three other throws that went to 60.10m, 56.60m and 58.13m before passing the last two attempts.
In other events of the day, Yash, a 17-year-old from Haryana, clinched the boys U-18 gold his opening throw of 67.42m in fading light.
It was the second best throw by an Indian U-18 athlete since September 2019.
Yash followed up his first throw with efforts of 65.21, 63.24, 64.05 and 65.46m before easing off with a 57.85m final throw.
Earlier, Delhi’s Disha won the girls U-16 event with a best throw of 34.87m.