Currently there are no tablets running Windows 10 as Microsoft has just launched 'Windows 10 Technical Preview'. If you wish to, you may run it on your laptop or desktop. The latest Windows tablets that are currently available in the market run Windows 8.1. The only Windows tablet available below Rs. 15000 in India is 'iBall WQ32'. It has a 8-inch display, 16 GB storage, Intel Atom Processor and 2GB RAM. It also has a micro SIM card slot which is used for 3G connectivity. You cannot make calls using this tablet.
Windows 10 devices are expected to be launched in Q1 of 2015. Since there are no tablets available under Rs. 15000 your best option is iBall WQ32.