Good to know that you are planning to invest in Raja Park. Raja Park is one of the best areas to invest in Jaipur in my opinion. The advantage of being connected directly to the national highway of Delhi and Agra is a great advantage.
While Raja Park may appear to be slightly out of the way from intercity connectivity, the Jaipur Metro is going to add a level playing field and I expect prices to appreciate substantially.
There are a number of local builders and developers active in the area of Raja Park and adjoining Tilak Nagar. Apart from the ones mentioned by the above member you can check out projects by Mahima real estate builders and developer private limited and Upasana Group.
Raja Park located on the north eastern to central regional axis is one of the better known areas of Jaipur. Raja Park and its adjoining area of Tilak Nagar have witnessed a substantial user interest in the real estate sector.
There are a number of domestic builders active in the area offering low rise buildings with various apartment sizes. Some of the well reputed builders active in Raja Park are Sand Dune construction private limited and Shivgyan Developers private limited.