@hbksabhi
I suggest visiting a few furniture shops and looking at various ergonomically designed office computer chairs.
I picked one up recently and find it really comfortable, esp. for an extended period of time. They are priced at upwards of 5K, the good ones that is.
You really need to try them out in person, to see if you're comfortable.
Bean bags, although quite comfortable (cozy), are not recommended for extended periods of computer usage.
Saving money on chair is not worth the risk to your health IMO
Amen!