51-70k Suggest Good Laptop Brand in India

If your work is not too demanding specs wise maybe consider a thinkpad. They are built really welll and last you much longer than most other brands. Else if a new thinkpad seems too costly why not just find something used that suits you?
 
You have not mentioned your budget. My personal preference has mostly been Dell>HP>Lenovo. You will not get a proper good long lasting laptop below 30K. For average ecommerce work (cataloging/listing/order management) any laptop with core i3+16GB RAM+IPS display is sufficient. But I will suggest to get an i5 processor based laptop to keep things going smoothly for longer time.
 
If your work is mostly on the browser, you can even consider a Chromebook+ device. I think this is quite a hot take, especially a techie forum like TE, though.
Otherwise, might I suggest M1 Macbook Air? It's still an excellent laptop, and can handle most tasks with ease, and with offers, you can get it for 50 to 60k.

Aside from that, if you're not into refurbished, don't go for Thinkpads, they're priced high for what they usually are. My suggestion would be to go for Ideapad or other Lenovo options, and keep Asus as another option. Dell is usually expensive, or confusing.