Hello, UmeshMD.
Welcome to Apple Support Communities.
From reading your post, we understand that you want a zoom on the keyboard when typing in your passcode. Have you checked out all of the Zoom features in this article: Zoom in on the iPhone screen
"Use Zoom
- Double-tap the screen with three fingers or use accessibility shortcuts to turn on Zoom.
- To see more of the screen, do any of the following:
- Adjust the magnification: Double-tap the screen with three fingers (without lifting your fingers after the second tap), then drag up or down. Or triple-tap with three fingers, then drag the Zoom Level slider.
- Move the Zoom lens: (Window Zoom) Drag the handle at the bottom of the Zoom lens.
- Pan to another area: (Full Screen Zoom) Drag the screen with three fingers.
- To adjust the settings with the Zoom menu, triple-tap with three fingers, then adjust any of the following:
- Choose Region: Choose Full Screen Zoom or Window Zoom.
- Resize Lens: (Window Zoom) Tap Resize Lens, then drag any of the round handles that appear.
- Choose Filter: Choose Inverted, Grayscale, Grayscale Inverted, or Low Light.
- Show Controller: Show the Zoom Controller".
You can always use this link to submit feedback on features you'd like to see implemented: Feedback
Cheers!