Dear Ramananand,
Prof. Kumar amply touched upon the subject covering even MSME and IEC registration.
MSME registration is not mandatory but it is advised to obtain it. There is no hassle in getting it. Now the procedure is very simple. It is at Free of Cost and paperless. There is no need of any agent to do it. It is now called as Udyam Registration. This will help you to avail certain loans / benefits by Govt.
IEC registration is mandatory for export from India or Import to India.
Since more than 10 employees at workplace, POSH compliance needs to be done. Violation will attract heavy penalty as well as cancellation of all your business licences.
ESI is applicable except in Maharashtra. In Maharashtra, ESI is applicable to shops and commercial on 20 and more coverable employees. If your software company is treated as factory under ESI Act then ESI would be applicable.
When you are looking to setting up a company, you need to first decide on what kind of company you want to form such as Propriety, Partnership, LLP, Pvt. Limited etc. and proceed further.