Master not discovered or elected yet, an election requires a node with id [eJcn6jOSRw65wy4liDC1VA]

Hi,
I am using 7.6 version.When I am trying to run elasticsearch bat file,I am facing with following errors

[2020-03-24T08:43:26,869][INFO ][o.e.n.Node               ] [10INLPC0SP3TF] initialized
[2020-03-24T08:43:26,871][INFO ][o.e.n.Node               ] [10INLPC0SP3TF] starting ...
[2020-03-24T08:43:29,163][INFO ][o.e.t.TransportService   ] [10INLPC0SP3TF] publish_address {127.0.0.1:9300}, bound_addresses {127.0.0.1:9300}, {[::1]:9300}
[2020-03-24T08:43:30,750][WARN ][o.e.b.BootstrapChecks    ] [10INLPC0SP3TF] the default discovery settings are unsuitable for production use; at least one of [discovery.seed_hosts, discovery.seed_providers, cluster.initial_master_nodes] must be configured
[2020-03-24T08:43:30,753][INFO ][o.e.c.c.Coordinator      ] [10INLPC0SP3TF] cluster UUID [72nwmnzFTymrr1_BukN2ug]
[2020-03-24T08:43:30,771][INFO ][o.e.c.c.ClusterBootstrapService] [10INLPC0SP3TF] no discovery configuration found, will perform best-effort cluster bootstrapping after [3s] unless existing master is discovered
[2020-03-24T08:43:40,776][WARN ][o.e.c.c.ClusterFormationFailureHelper] [10INLPC0SP3TF] master not discovered or elected yet, an election requires a node with id [eJcn6jOSRw65wy4liDC1VA], have discovered [{10INLPC0SP3TF}{1Farf6X-R1u0LM6KNgh4Kw}{Opa4KPSPQkSu-XhuvHEPHA}{127.0.0.1}{127.0.0.1:9300}{dilm}{ml.machine_memory=17010958336, xpack.installed=true, ml.max_open_jobs=20}] which is not a quorum; discovery will continue using [127.0.0.1:9301, 127.0.0.1:9302, 127.0.0.1:9303, 127.0.0.1:9304, 127.0.0.1:9305, [::1]:9301, [::1]:9302, [::1]:9303, [::1]:9304, [::1]:9305] from hosts providers and [{10INLPC0SP3TF}{1Farf6X-R1u0LM6KNgh4Kw}{Opa4KPSPQkSu-XhuvHEPHA}{127.0.0.1}{127.0.0.1:9300}{dilm}{ml.machine_memory=17010958336, xpack.installed=true, ml.max_open_jobs=20}] from last-known cluster state; node term 64, last-accepted version 5031 in term 64
[2020-03-24T08:44:00,798][WARN ][o.e.n.Node               ] [10INLPC0SP3TF] timed out while waiting for initial discovery state - timeout: 30s
[2020-03-24T08:46:03,928][INFO ][o.e.h.AbstractHttpServerTransport] [10INLPC0SP3TF] publish_address {127.0.0.1:9200}, bound_addresses {127.0.0.1:9200}, {[::1]:9200}
[2020-03-24T08:46:03,929][INFO ][o.e.n.Node               ] [10INLPC0SP3TF] started
[2020-03-24T08:46:12,602][WARN ][o.e.c.c.ClusterFormationFailureHelper] [10INLPC0SP3TF] master not discovered or elected yet, an election requires a node with id [eJcn6jOSRw65wy4liDC1VA], have discovered [{10INLPC0SP3TF}{1Farf6X-R1u0LM6KNgh4Kw}{Opa4KPSPQkSu-XhuvHEPHA}{127.0.0.1}{127.0.0.1:9300}{dilm}{ml.machine_memory=17010958336, xpack.installed=true, ml.max_open_jobs=20}] which is not a quorum; discovery will continue using [127.0.0.1:9301, 127.0.0.1:9302, 127.0.0.1:9303, 127.0.0.1:9304, 127.0.0.1:9305, [::1]:9301, [::1]:9302, [::1]:9303, [::1]:9304, [::1]:9305] from hosts providers and [{10INLPC0SP3TF}{1Farf6X-R1u0LM6KNgh4Kw}{Opa4KPSPQkSu-XhuvHEPHA}{127.0.0.1}{127.0.0.1:9300}{dilm}{ml.machine_memory=17010958336, xpack.installed=true, ml.max_open_jobs=20}] from last-known cluster state; node term 64, last-accepted version 5031 in term 64

I just installed the elastic search and run the batch file.Previously I was using 7.4 version.
It is working fine but when I am using 7.6 It is showing the above errors.

I think the most likely cause is that you had two nodes running at once (both the 7.4 and 7.6 one perhaps) and they formed themselves into a two-node cluster. You've now removed one of them, which is half of them, so you have lost quorum.

Assuming this is a brand-new node, the simplest fix is to delete its data path and let it start again from the beginning.

How to delete its data path?

I don't really understand the question. Assuming you're running Windows, find the data path in Windows Explorer and delete it.

okay