There are numerous Cons to mention.
1. Rural posting anywhere in India. This has lots of issues especially language barrier in reading and writing official or loan documents.
2. No work life balance
3. Branches has less infrastructure and resources. Even cash counting machines are not available in many branches.
4. No flexibility for vacation as the replacement is seldom available.
5. High risk job as anything missing will be the officer's responsibility.
6. Difficult to stay with family as there are frequent transfers.
In my opinion, working in Syndicate Bank is not worth your time and effort. One can be better off working in an MNC in India or abroad. I did the same and it was the right decision and cannot be more happy about this decision.