Your money does not sit with the fund house. It goes to a custodian, a separate regulated institution that holds the securities on behalf of all unit holders. The fund house manages; the custodian keeps. Neither can touch the money for its own use.
A registrar and transfer agent (an RTA such as CAMS or KFintech) keeps the record of who owns how many units. When you invest through Crowwd, your units are recorded against your name and PAN at the RTA, not against Crowwd. If Crowwd disappeared tomorrow, your units would still be yours.
The fund manager then deploys the pooled money according to the mandate: into shares, bonds, gold, or short-term instruments. Every holding is disclosed monthly in the fund's factsheet, so you can always see exactly what you own.
Your units sit with the registrar in your name. The platform is a window, not a vault.