Dear CSIA or Not:
Abbreviations may have different meanings across countries, and sometimes even within a country. We are assuming that you are referring to the CSIA designation offered by the Information Systems Audit and Control Association & Foundation of the USA. with chapters around the world.
As you may know, CISA is not a course of study or training, it is a certification of your competency in computer systems audits. It does not offer you any additional knowledge or experience, but merely confirms that you have such knowledge and experience. You need to have the knowledge and experience to get the certification, not the other way around - CISA is not intended to grant a certificate to practice, but to certify that you are proficient in the practice. The lack of such certification does not signify that you do not have the competency to which CSIA attests. So, is it worth it? Perhaps! You must keep in mind however that the employer in the private sector, whether in India or elsewhere, is more interested in your talents and skills than the various certifications you have collected over the years. While degrees and certifications are important for the employer at the entry-levels jobs, such is not the case beyond that. Your employment record and performance can demonstrate your competency in computer systems audit, without the CISA designation. Even the body conducting the CISA acknowledges that "the certification may not be mandatory for you at this time, but. " In fact, they do not list a single
job in a single country for which the CISA is required.
Some disciplines - such as medicine, audit, construction, plumbing, etc. - require formal credentials, but a vast majority of jobs do not. For example, Professional Engineering (PE) certification in the US is required for signing official documents. However, a vast majority of engineers in the US do not have PE, precisely because it merely certifies your credentials and does not offer you any additional knowledge or skills - and, most employers do not care. Employers care for a certification only when some bureaucratic requirement forces them to care. They are most interested in what you can do for them, not in your certifications.
You ability to move abroad - to the US or UK - for employment is independent of the CISA designation. If your skills are in demand and the domestic market can not provide the talent, employers have the ability to bring in a limited number of highly skilled workers from abroad. So you need a job offer, on which CISA designation is likely to have zero impact; your job prospects are not dependent on CISA.
Chartered Accountant (CA) certification is not recognized outside of India, as you have correctly noted. While basic accounting principals are the same, local practices vary dramatically. The Certified Public Accountant (CPA) certification in the US is similar to that of CA in India. Should you end up in the US and you wish to leverage your CA education, you would have to take the CPA exam.