What legal steps can I take to protect my investment?

I am seeking legal advice regarding a health tech start-up in which I invested, along with 97 other investors, raising over INR 100 crore in January 2024. The founders promised an IPO by April 2024 and assured us of 4x returns, issuing post-dated cheques to reflect these returns. However, the IPO did not occur, and I received post-dated cheques for January 2025. Some investors who were given cheques for September 2024 encountered issues when the company issued a stop payment on those cheques to avoid bouncing. Although the founders are credible, they have asked us to refrain from legal action until the end of 2024, as they are attempting to secure another round of funding. My first question is whether there is anything I can do now to protect my interests while waiting. Secondly, what are my legal options if I choose to take action immediately, and how can I safeguard my investment and enforce the post-dated cheques if necessary?