In the price range of 15,000 to 20,000 rupees in Pakistan, you can find smartphones with decent specifications and features. Here are a few examples:
Xiaomi Redmi 8A:
This phone has a 6.22-inch HD+ display, an octa-core Qualcomm Snapdragon 439 processor, 2GB/3GB/4GB of RAM and 32GB/64GB of storage, a 5000mAh battery, and a 13-megapixel rear camera. It runs on Android Version 9 with MIUI 11.
Realme Narzo 30A:
This phone has a 6.5-inch HD+ display, an octa-core MediaTek Helio G85 processor, 3GB/4GB of RAM and 32GB/64GB of storage, a 6000mAh battery, and a 13-megapixel main + 2-megapixel depth sensor dual rear camera. It runs on Android Version 11 with Realme UI 2.0
Samsung Galaxy M02s:
The phone features a 6.5-inch HD+ display, a quad-core Qualcomm Snapdragon 450 processor, 2GB/3GB/4GB of RAM and 32GB/64GB of storage, a 5000mAh battery, and a 13-megapixel main + 2-megapixel depth sensor dual rear camera. It runs on Android version 11 with One UI 3.1
Huawei Y6p:
This phone has a 6.3-inch HD+ display, a octa-core MediaTek Helio P22 processor, 3GB/4GB of RAM and 32GB/64GB of storage, a 5000mAh battery, and a 13-megapixel main + 2-megapixel depth sensor dual rear camera. It runs on Android 10 with EMUI 10.1
Oppo A53:
This phone has a 6.5-inch HD+ display, a octa-core Qualcomm Snapdragon 460 processor, 3GB/4GB/6GB of RAM and 32GB/64GB of storage, a 5000mAh battery, and a 13-megapixel main + 2-megapixel depth sensor dual rear camera. It runs on Android 10 with ColorOS 7.2
Vivo Y51:
This phone has a 6.58-inch FHD+ display, a octa-core Qualcomm Snapdragon 665 processor, 4GB/6GB of RAM and 128GB of storage, a 5000mAh battery, and a 48-megapixel main + 8-megapixel ultrawide + 2-megapixel macro triple rear camera. It runs on Android version 11 with OS 11 Funtouch.
It's always a good idea to double check the specs and availability with retail shop or online marketplaces before making any decision.