Calangute and Panaji have Reebok, Addids, Fila, La Coste shops etc.. Can't say I have seen much more than this, and what they do have are short on sizes and stock.
As for the markets - have a very good look before buying, some very poor copys - but also some very good ones !

I have noticed recently (in the sales!) that lots of H&M, Monsoon, Zara, topshop etc clothing are made in India, but we hardly saw any when we are there! Did we miss anything, or is it generally all exported?

The simple answer is that, yes, the clothes that you find in the shops you list might well be made in India (especially Monsoon) but to designs and specifications developed by the buying team of the chain concerned. The garments will have been made specifically for the export market and while you might strike lucky and find an outlet in India that sells surplus over runs or seconds, you won't find much of it generally available.

This is a bit like one of my students from Africa saying that despite the large quantities of cotton batik fabric that they could buy at home being produced in Britain, they were surprised at how little they saw over here. On the whole, we in Britain don't wear such wraps and gowns and nearly everything that is produced was exported and they are still only available from specialist outlets. As luck would have it, I did have good contacts in the Lancashire cotton trade at the time and was able to arrange for this particular student visitor to go direct to a couple of the factory shops in Manchester where she was able to buy a lot of fabric very much more cheaply than she could at home. This wouldn't be the case now because the Lancashire cotton trade has all but collapsed and though a subsidiary of Tootal still produces such high quality batik printed fabric they have shifted production to Africa in order to save money! Hence why I went on a holiday to Gambia a couple of years ago with the intention of buying batik fabric to bring back with me.

Similarly, the bulk of cashmere production in Scotland is done with the export market in mind. A great deal of the cashmere knitwear available in the big chain stores in the UK is actually made in China - because it's cheaper - and the high end designer stuff finds its way into upmarket boutiques in Europe and just a few select outlets here. The most garish cashmere golfing sweaters head off to the US but US golfers visiting Scotland need to seek out very carefully the stuff which they'll be used to at home because most British golfers are a lot more conservative in their tastes and wouldn't be seen dead in much of the stuff that we make here but send across the pond!