Bajaj Pulsar NS200

A good upgrade without sacrificing mileage from your 100cc Platina would be something in the 150-160cc space, like the Bajaj Pulsar N160, TVS Apache RTR 160 4V, Suzuki Gixxer, Honda Unicorn/SP160, or the Yamaha FZ lineup. If you want to go beyond that, the TVS Apache RTR 200 4V, Honda Hornet 2.0 or Bajaj Pulsar NS200 will fit the bill. Take a long test ride to see which option suits you best. 

There are two types of bikes you can consider - sporty, liquid-cooled 160cc streetfighters and air-cooled, sporty-looking 160cc commuter bikes. In the former category, your options are the KTM 160 Duke and Yamaha MT-15, while in the latter, bikes like the Bajaj Pulsar N160 and TVS Apache RTR 160 4V can be considered. 

If you don't mind lower fuel efficiency, then the Bajaj Pulsar NS200 can also be a fun option within your budget. Another option that can be considered is the Royal Enfield Hunter 350, which will have a very different engine feel from any other option listed above, but will be comfortable and decently fuel-efficient. Something you can also consider if you're open to an ADV is the Hero Xpulse 210, which ticks all the boxes you want.