Can I swap sabji Masala for Tandoori Masala in this recipe?
Spice mixes tend to vary quite a lot from recipe to recipe. If you go to an Indian shop and compare a few brands of tandoori masala (or search online for different recipes) you'll probably notice that there are quite large differences in both the quantity and types of spices used. I've tried a few packaged tandoori masala and have tried a few recipes and they can definitely vary quite a bit in flavour. I'm sure the same is true of the sabji masala.

In all likelihood, most of the spices would be present in both mixes. Without knowing the specific spices used in your mixes, however, it's hard to say exactly what would be different. Some spices are quite distinctive - i.e. the sabji masala might have fenugreek leaves (kasoori methi) which have a pronounced flavour, but then again, some tandoori masalas also include it.

Whatever spices used, I think the tandoori masala will work fine in the recipe.