I think a FHD+ display is a must in today's world, so won't recommend the Narzo 30A.
If you want a clean UI, then Micromax IN Note 1 is the only option but if you're fine with MIUI then either the Poco M3 or the Redmi 9 Power based on your preference.
Each of these would cost you around 10k with CC offers.
Normaly I don't recommend Nokia but since the person is an elder, if you can stretch your budget, get a Nokia G20.
Ads and other nagware can get quite intimidating. Besides they ain't tech savvy to debloat their phones and stuff.
Only caveat is screen is HD+ and it costs around 12k.
If there is someone tech-savvy in the house who can guide the person then go with any of the above mentioned brands.