What are the cheapest smartphones under 26 k?

You can get many options….

there is some example for you

Redmi k20

• 6 GB RAM | 128 GB ROM
• 16.23 cm (6.39 inch) Full HD+ Display
• 48MP + 13MP + 8MP | 20MP Front Camera
• 4000 mAh Li-polymer Battery
• Qualcomm Snapdragon 730 Processor

LG v30+

• 4 GB RAM | 128 GB ROM | Expandable Upto 2 TB
• 15.24 cm (6 inch) Quad HD+ Display
• 16MP + 13MP | 5MP Front Camera
• 3300 mAh Battery
• Qualcomm Snapdragon 835 Processor

Vivo V17

• 8 GB RAM | 128 GB ROM | Expandable Upto 256 GB
• 16.36 cm (6.44 inch) Full HD Display
• 48MP Rear Camera
• 4500 mAh Battery
• Qualcomm Snapdragon Processor

samsung Galaxy S7

• 4 GB RAM | 32 GB ROM | Expandable Upto 200 GB
• 12.95 cm (5.1 inch) Quad HD Display
• 12MP Rear Camera | 5MP Front Camera
• 3000 mAh Li-Ion Battery
• Exynos 8890 Octa Core 2.3GHz Processor

Samsung Galaxy a50s

• 4 GB RAM | 128 GB ROM
• 16.26 cm (6.4 inch) Full HD+ Display
• 48MP + 5MP + 8MP | 32MP Front Camera
• 4000 mAh Li-ion Battery
• Exynos 9611 Processor

Oppo f11 Pro

• 6 GB RAM | 64 GB ROM | Expandable Upto 256 GB
• 16.51 cm (6.5 inch) Full HD+ Display
• 48MP + 5MP | 16MP Front Camera
• 4000 mAh Li-polymer Battery
• MediaTek Helio P70 Octa Core 2.1 GHz Processor
• VOOC Charging
• Pop-up Camera

Honor 20

6 GB RAM | 128 GB ROM

15.9 cm (6.26 inch) Display

48MP + 2MP + 16MP | 32MP Front Camera

3750 mAh Battery

HiSilicon Kirin 980 Processor