Hello Akkshay1594,
For assistance with any physical issue with your iPhone it will be necessary to rely on available service options in your region. You can review options available to you on the following page: Find Locations
If the page does not automatically update to your region you can select it in the bottom right corner, then select Service & Support. We would like to highlight that unless there is a performance issue with your device it may not qualify for service under limited warranty. Specifically,
"This Warranty does not apply: (a) to consumable parts, such as batteries or protective coatings that are designed to diminish over time, unless failure has occurred due to a defect in materials or workmanship; (b) to cosmetic damage, including but not limited to scratches, dents and broken plastic on ports unless failure has occurred due to a defect in materials or workmanship;"
This information and more can be found here: Legal - iOS Warranty Document Us - Apple
Best regards.