At your budget, you can opt for Hindustan Unilever Pureit or Tata Swach or Eureka Forbes Aquasure for the water purifier. All three work on basically the same principles, and there is nothing much to separate them. I am personally using Pureit, and I find nothing wrong with it.
For the microwave, I think you will have to settle with either a solo microwave or a grill microwave (A grill microwave offers more cooking techniques). You do have a lot of options, brandwise, in this category. Again, I have personally used the LG solo microwave and the IFB grill microwave, and personally find nothing much to differentiate between the two in terms of quality. Both do their job well. So choose something from a brand you prefer/like.