What is the process for applying visa for child born in UK? The parents are on Tier 2 ICT and still have 2 years left on their visas. After securing a Indian passport for the child, what is the process to apply for child's UK visa?
Babies who are born in the UK who do not have a claim to citizenship or permanent residence have a special status which, for lack of a better word, is "tolerated". So they don't need a visa initially, but they do need a passport issued by their home country.
The "tolerated" status lasts until the child leaves the UK or until the child reaches 10. Normally the first condition applies, i.e., the child will leave the UK with one of the parents on a holiday or whatever. Once the child is outside of the UK they must obtain an entry clearance as a dependent, exactly in the same way you did, by making an application (you must do it for them or on their behalf). Since a T2 ICT dependent visa must be obtained in the applicant's home country, the parents should avoid a trip to Spain for example because a T2 application cannot be made there.
The other case, where the child reaches 10 never having left the UK, gives the child an automatic claim to British citizenship. Based on what you wrote, it is unlikely the child will take this route.
Also note that the Authorising Officer at your ICT in the UK should know all of this and should be able to answer further questions you might have.