Andy Fleming wrote :

could you please help me find an alternative for beetroot powder as i am
unable to find it anywhere.

Pat Chapman strikes again! I would bet that you are using a Pat 
Chapman recipe.  I go to many Asian grocers and spice merchants 
and I too have never come across beetroot powder for sale in my 
travels.

OK, as far as I understand it, Pat started recommending beetroot 
powder instead of artificial colouring. So beetroot powder was itself a
substitute. Therefore you could go back to the original and use
red food colouring. Except food colouring isn't the original 
because restaurants use it instead of the deep red Kashmiri chilli 
powder used in authentic recipes.

If you wanted to stay with natural products then you could go back to 
the authentic ingredients and increase the chilli powder or add extra 
paprika. Another possibility is to grill slices of sweet red pepper, 
skin them and puree them in a blender. The latter only really works for 
"wet" curries but not marinades as they become too runny.

Another option for wet curries is to buy boiled ( but NOT pickled) 
baby beets from the supermarket and puree them in a blender. Of 
course this gives the intended colour and also thickens the curry 
BUT will obviously add a beetroot flavour.

I tend to use a little food colouring and extra paprika if I want a
deep red colour in a curry.

So you pays your money and you takes your choice.