You're certainly within the normal range among all governmental recommendations that I'm aware of (including relatively stringent definitions like the Japanese government). BMIs below 18.5 are associated with increased risk of death, as are BMIs over 25. I'd suggest checking your body fat percentage and evaluating from there: BMI is a somewhat limited measure to determine overall health, but can be useful for quickly diagnosing extreme (obesity/overweight/underweight). At this point, you should probably focus on other fitness outcomes than just weight: strength, flexibility, blood lipids (HDL/LDL, trigycerides, etc), blood glucose, subjective appearance, waist circumference, body fat percentage, etc.
That said, south Asians do have a significantly elevated genetic risk of type II diabetes relative to most Europeans or east Asians, so maintaining a low BMI is likely to significantly improve your health. Indeed, a BMI over 23 is considered a risk factor for diabetes in south Asians, and while you're not close to that BMI any more, getting farther away from it might reduce your risk of diabetes.
Overall though, good job! And remember that weight maintenance is frequently harder than actively losing weight, so you'll probably have to stay vigilant to even maintain your losses. Dr. Arya Sharma put it very well in this video about Weight-Loss Plateaus.
The important part is continuing to maintain healthy diet and exercise habits, not necessarily to lose ever more weight.