Buying property with tenants living in

Dear experts, I'm purchasing an apartment in gurgaon in resale, and currently the property has tenants(bachelors) staying in it. They have rent agreement with current owner till May 2019(with minimum 6 months lock in period ending [deleted], thereafter 1 month notice can be served by either tenant/owner to leave) 1. To safeguard my rights as buyer, I have asked for registry to happen on 2 Jan 19, i.e. post the minimum lockin period expires as owner says they will get tenant leave by 31 Dec, due to lockin period. But I'm having doubts if tenants refuse to vacate stating its only minimum lock in period, and they will vacate only when 11 month lease expires(May 2019). 2. Apart from above, I propose to have 2 options below, kindly suggest the most feasible and practical one : a) Would I be better off in doing token now, and doing ATS once tenant vacates the premises. b). Shall I ask seller to send notice to tenants to vacate by 30-Nov-18 and have a copy of notice, along with tenant's receiving on it. 3. Any other better option you suggest, which is feasible and safeguards buyers interest in such cases. Kindly advice. Regards-NN