Though I appreciate your interest in enhancing your HR knowledge, please specify your current experience and your future desires. Are you into recruitment or an HR generalist? Also, what do you want to specialize in?
Specialized Sub-functions in HR
Performance management, training, talent acquisition, HR strategy, HR analytics, employee engagement, payroll, and so on are the specialized sub-functions one can choose based on the skills within the HR function.
Gaining Practical Experience
My suggestion is, as you already have an MBA in HR and just 2.5 years of work experience, please focus on gaining practical experience in HR within your company. Understand the structure of your company, its business, financials, and the HR function. Know your company's financial performance, and try to identify strengths and opportunities. This may seem overwhelming with only 2.5 years of experience, but still, give it a try.
Think about how you can enhance the capabilities of the people in your organization and create value. It's high time for HR departments to move from traditional practices to align with industry needs, so apply innovative thoughts in your work.
Considering Certificate Courses
By doing this, you will learn a lot on your own and through mentors. Once you reach 5 years of experience, you can consider certificate courses. There are many premier institutes that offer HR certificate courses (such as IIM, XLRI). These courses have great credibility, and having 4 or 5 years of experience would be beneficial as they are well-developed.
Instead of focusing solely on books and certificates for knowledge at your current experience level, focus on learning independently and through mentors. After another 2 years, you can decide what you want to study. You will have a better understanding and be able to relate things, bringing more value to your work.
So, relax for now, just my 2 cents though! It all depends on you.
Good luck.
Regards, Thiyagu