Immigrationboards.com

Hi,
I am in India for the past 1 year with a valid UK ILR.
How long can I stay outside the UK that doesn't make my ILR invalid?
Has anything changed with BRITEXIT?

Two years. But short visits do not reset the clock. You need to resume residence in the UK within two years. ILR has got nothing to do with EU law, therefore no impact of Brexit.

Also see this post on a similar topic.

A returning resident should return to the UK, for the purpose of settlement, within two years.