Hi Vipendra Singh,
Please have a look at the guidance on residence at RDR3
To help determine your tax residence for the tax year in which you return to India and whether split year treatment applies.
RDR3 Statutory Residence Test
You may find that if you are tax resident in the UK for the whole tax year, you will have to report any capital gains arising in the tax year that you leave the UK.
In future tax years, where you are not UK resident, there will be no UK capital gains tax to pay on any gains arising from your investment activities via your broker.
You will have to declare the gains in India.
Thank you.