Nanjing offers special subsidies for overseas returnee / international talent entrepreneurship (rent subsidy + startup seed funding). Social insurance rate ~38%, minimum base approximately ¥5,000/month.
Nanjing has a dense concentration of universities and research institutions but lags behind Hangzhou in startup activity — more graduates prefer government jobs or large companies over entrepreneurship. If you depend on an active startup community and peer exchange, Hangzhou may offer more atmosphere.
Nanjing is a major chip hub (TSMC Nanjing fab, Unisoc, etc.), but chip startups require tens of millions in initial funding. If you are doing a semiconductor-related OPC, consider entering from lighter-asset angles like chip design services or EDA tools.
Jiangbei New Area's startup subsidies and tax incentives have clear application windows. Check the validity periods and renewal conditions of current policies before settling in.