The UK Business Visitor visa is being abolished in about 5 weeks, so depending upon your time frame, the question may become obsolete. The category will no longer exist...
. In paragraph 6, delete “A "Business Visitor" is a person granted
leave to enter or remain in the UK under paragraphs 46G-46L, 75A-F or
75G-M of these Rules.“
If you want to reapply before 6 April, you wouldn't level down to a general visitor application because it's the wrong class of visa for attending a conference. The best strategy is to fix their objections and make a fresh application as a business visitor.
If you decide to wait until after 6 April, you can apply for the new Visitor (standard) visa. The process may be simpler for you, but they will still take the circumstances resulting in your refusal into account.
Overall using one's parents as financial sponsors is a weak strategy unless the parents are based in the UK and have signed an undertaking. A much stronger strategy is to give evidence that you have your own funds available to you for the purposes of your visit. And most importantly, that you acquired those funds as part of a persistent and on-going life in India.
The new rules state (in part)...
A visitor’s travel, maintenance and accommodation may be provided by a
third party where the decision maker is satisfied that they:
- have a genuine professional or personal relationship with the visitor; and
- are legally present in the UK, or will be at the time of the visitor’s entry to the UK; and
- can and will provide support to the visitor for the intended duration of their stay.