PF - employer is running 3 or more contracts in various companies and each company the employer deploys less than 10 employees

If an employer is running 3 or more contracts in various companies and each company the employer deploys less than 10 employees but cumulative employees in the firm is more than 20 so it is necessary for employer to register in PF act and deduct pf of each employees those working in the same firm but in separate contract.

Yes, you as an employer has to open PF a/cs of all under your umbrella and remit recovered PF contributions in these a/cs regularly to avert violations & penalty.