Thanks for your further questions
Whether you have income from India or in the UK, it will all be liable to UK tax , as you will be treated as resident throughout this and following tax years (based on what you have advised me) so remain liable to tax on worldwide income.
The tax position for capital gain purposes, are as follows -
If your annual income is in excess of £42,475 a year, then the gain will all be liable to 28%.
If you annual income is more than £9440 and less than £42,475, then any unused basic rate band, can be used to allow the equivalent amount of gain at 18% and any further gain at 28%
So for example your annual income is £30,000 then you have £12,475 unused basic rate band (£42474 less £30,000) so the first £12,475 of the gain will be at 18% and the remaining gain at 28% (of course these rates are applied, after costs, capital improvements, reliefs and annual exemption allowance have been applied)
Maintenance, if general repairs are not deductible, they can only be allowed as a deduction against the gain IF capital improvement such as total new kitchen, bathroom and so on and yes you would need to have evidence of these costs, should HMRC ask for them.