Jainagar is Taluka (Tehsil) in Koderma district of Jharkhand state. Jainagar has 8 areas (postal offices).
| Pin code | Area | District | Taluka | Postal Status |
|---|---|---|---|---|
| 825109 | Chalkusa PIN Code | Koderma | Jainagar | Branch Office |
| 825109 | Chaubey PIN Code | Koderma | Jainagar | Branch Office |
| 825109 | Dandadih PIN Code | Koderma | Jainagar | Branch Office |
| 825109 | Jainagar Koderma PIN Code | Koderma | Jainagar | Sub Office |
| 825109 | Maskedih PIN Code | Koderma | Jainagar | Branch Office |
| 825109 | Naitand PIN Code | Koderma | Jainagar | Branch Office |
| 825109 | Sharmatand PIN Code | Koderma | Jainagar | Branch Office |
| 825109 | Sudan PIN Code | Koderma | Jainagar | Branch Office |