There's nothing Chinese fear more from India than an Indian SSBN fleet and SLBM tests. I guess much of the Wuhan-Mahabalipuram shitshow was a Chinese attempt to get India to go slow on its SSN/SSBN fleet-building, in return for peace, trade, and diplomatic dog-biscuits such as Chinese approval for blacklisting paki terrorists, etc.
Although we have the range, the most we can pull off is hitting Kunming or Chengdu from a missile launched from land. Hitting Beijing and Shanghai are only a theoretical possibility due to the response time chicoms have.
On the other hand, a volley from even four Indian SSBNs in the East- and South China Seas spells doom for Shanghai, Tianjin, Xiamen, Guangzhou, and Beijing.
Just as Pakis decided in the 1980s that "we must eat grass but have the ability to nuke even far-off Tamil Nadu," India must build an SSBN fleet, event if it causes a major economic crisis.