Actually my taizong is for Zheng , and Ho for a japanese , BTW , pls provide more info for Vijayanagara
Here is my knowledge on the subject and i'll leave it to you guys to determine what you want to use from it.
First off, it was the Vijaynagar Empire, Vijayanagara was the name of the capital city that laid the foundation of the empire; much like how the city of ROME is different from ROMAN EMPIRE. The Vijaynagar Empire was started by Madhav Vidyaranya and his brother Sayana when they founded the capital city of Vijayanagara in 1374, as they fought the northern hindu states and and the muslim sultanates, although they are not as important to the empire's history as others. For the next two centuries the empire expanded to encompass all of southern india.
The two most important leaders of the empire were Krishnadevaraya (reigned 1509-1529) and Achyutaraya (reigned 1529-1542). They vastly expanded the borders of the empire, established diplomatic contacts with the great asian powers (specifically Ming China), as well as become kings that spent a lot of the empire's wealth on cultural improvements and war. Specifically, they made the Vijaynagar Empire into what it was to become, an economic and cultural giant; the netherlands of India and the Greece of the Subcontinent. The market of Vijayanagara became one of the leading economic markets in asia and in the world, especially when connected to the Mangalore, Honavar, Bhatkal ports on the eastern coast of the state. If one were to list the greatest cities in the world at the dawn of the sixteenth century Vijayanagara would be alonside Constantinople, Penking, and Paris. The Vijaynagar Empire established trading ties with china, southeast asia, and arabia, mostly securing military equipment, soldiers, and elephants, while exporting lucrative trade commodities like weavings and raw resources like cotton, indigo, spices, precious stones, and porcelaine.
The Empire was founded on warfare, and just as with greece, the Vijaynagar Empire had regular seasons of war, usually following the Mahanavami festival.
The Empire's administrative foundations lay in the unique quality of the Nayakas, warrior governors that furnished the Kings of Vijayanagara with troops, supplies, and equipment, while the kings provided the Nayakas with imperial money and services as well as generous donations to the temples that made up the Nayakas administrative districts, to govern and keep order in the kingdom. To keep order the kings and Nayakas allowed for religious freedom and established a maritime fleet that carried their goods to the corners of asia and africa, with permanent trade contacts in Aden, Mecca, Persian ports, Java, and Brunei.
In 1565, the empire lost a momentous battle to the muslims that caused the kings to abandon Vijayanagara, as the city lay on the empire's northern most border (the city lies on two river banks, in the middle of southern india, but the rivers connected it to the ocean. It's geographic and political/economic foundations were similar to Seville and the gualdilquivir river). this date represents the decline of the empire, but it does not represent it's collapse because it retained it's independance for another century. It's much like the defeat of the spanish armada really had little effect on the spanish (other than that they didn't conquer Enland) but it demonstrated they lacked the funds and the manpower to expand their domains and thus began to suffer political and economic setbacks from which they would never fully recover.
As to units, the empire was one of the first indian states to employ long ranged artillary manned by foreign gunners (usually from Turkistan). They had an army numbering at about 1.1 million with a significant amount them being infantry. They rarely relied on massive frontal assualts like the russians did though, and they only fought in strategic locations. THey had important and lasting trade relations with the portuguese in Goa and they provided the empire with musketeers and artillery. The empire depended on foreign trade, especially for military purposes; and when you make this state in the game, i hope you represent that.
I hope this helps you with creating the Vijaynagar Empire.