Hello ManivelR,
"Can i club all these 10 ESXi servers to make as a vSAN ? "
Likely not but this depends on more precisely what you have available and/or what you can add; vSAN requires a) true locally attached storage b) a combination of SSDs/NVMe for cache + HDDs/SSDs for capacity-tier (up to 7 per Disk-Group, 5 Disk-Groups per node) and c) components on the vSAN HCL.
"If there is any host failure or any disk failure,it will sustain failure ? or i need to get the same storage capacity from all the 10 ESXi servers to make as a vSAN ??"
vSAN protects data by placing mirrors of data-Objects on multiple Fault Domains - each node being a Fault Domain if not specified otherwise so for instance if you had a 10 node cluster with FTT=1 applied to the data it can tolerate one node failure and rebuild the data back to FTT=1. You don't necessarily need all nodes to contribute the same amount of storage (or technically some can have none) but this would be fairly imbalanced from a resilience perspective.
"We no need to configure any RAID from the hardware level right ? Please confirm."
No - RAID is applied at the data-Object level (and for some controllers RAID0 individual RAID0 VDs for each device).
Bob