suggest that if these border disputes were an ultimate deal...

suggest that if these border disputes were an ultimate deal breaker then India would not be in BRICS to begin with.

well I take your point ...up to a point .
India has from it's inception tried to be " Non Alligned" and has even tried to be freindly with China though the joining of QUAD and the banning of Tik Tok completely shows that this sibling has completely given up on that effort .
In summary Indai likes the idea of BRICS more than it can tolerate China which will limmit it's involvement .

For instance ...people were talking a BRICS currency whereas China pushes the RMB hard - don't expect India to support that .
Truth is , BRICS will always be limmited by two factors :
1.China - a taker rather than a giver
2. the west as a grouping , NATO for example has 43% of the worlds economies without Japan , Oz etc , have a big share of the worlds GDP

I'm prepared to accept that there may well be an increase in China's influence and perhaps BRICS but to think this grouping is showing ANY signs of being THE dominant world grouping could only be described as highly imaginative wishful thinking .