Finally, able to fix number of partition issues, however size of partition needs to be checked. Below is updated code, hope this helps. I will update if partition size is fixed as well.

d-i partman-auto/disk string /dev/sda
d-i partman-auto/method string lvm
d-i partman-lvm/device_remove_lvm boolean true
d-i partman-md/device_remove_md boolean true
d-i partman-auto-lvm/new_vg_name string main
d-i partman-auto-lvm/guided_size string max
d-i partman-auto/choose_recipe select multi
d-i partman-auto-lvm/new_vg_name string vgroot
d-i partman-auto/expert_recipe string                         \
      boot-root ::                                            \
              1024 10 1024 ext4                               \
                      $primary{ } $bootable{ }                \
                      method{ format } format{ }              \
                      use_filesystem{ } filesystem{ ext4 }    \
                      mountpoint{ /boot }                     \
              .                                               \
              100 11 -1 ext4 $primary{ }              \
                      $defaultignore{ }                       \
                      method{ lvm }                           \
                      device{ /dev/sda }                     \
                      vg_name{ vgroot }                       \
              .                                               \
              4096 20 5120 ext4                              \
                      $lvmok{ }                               \
                      in_vg{ vgroot }                         \
                      lv_name{ lvopt  }                       \
                      method{ lvm } format{ }                 \
                      use_filesystem{ } filesystem{ ext4 }    \
                      mountpoint{ /opt }                      \
              .                                               \
              1900 60 2000 ext4                              \
                      $lvmok{ }                               \
                      in_vg{ vgroot }                         \
                      lv_name{ lvhome  }                      \
                      method{ lvm } format{ }                 \
                      use_filesystem{ } filesystem{ ext4 }    \
                      mountpoint{ /home }                     \
              .                                               \
              7168 30 8192 ext4                              \
                      $lvmok{ }                               \
                      in_vg{ vgroot }                         \
                      lv_name{ lvvar  }                       \
                      method{ lvm } format{ }                 \
                      use_filesystem{ } filesystem{ ext4 }    \
                      mountpoint{ /var }                      \
              .                                               \
              4096 40 5120 ext4                             \
                      $lvmok{ }                               \
                      in_vg{ vgroot }                         \
                      lv_name{ lvtmp  }                       \
                      method{ lvm } format{ }                 \
                      use_filesystem{ } filesystem{ ext4 }    \
                      mountpoint{ /tmp }                      \
              .                                               \
              4096 50 5120 ext4                             \
                      $lvmok{ }                               \
                      in_vg{ vgroot }                         \
                      lv_name{ lvvartmp  }                    \
                      method{ lvm } format{ }                 \
                      use_filesystem{ } filesystem{ ext4 }    \
                      mountpoint{ /var/tmp }                  \
              .                                               \
              2000 12 2000 linux-swap                        \
                      $lvmok{ }                               \
                      in_vg{ vgroot }                         \
                      lv_name{ lvswap  }                      \
                      method{ swap } format{ }                \
              .                                               \
              9216 15 10240 ext4                             \
                      $lvmok{ }                               \
                      in_vg{ vgroot }                         \
                      lv_name{ lvroot  }                      \
                      method{ lvm } format{ }                 \
                      use_filesystem{ } filesystem{ ext4 }    \
                      mountpoint{ / }                         \
              .                                               \

d-i partman-partitioning/confirm_write_new_label boolean true
d-i partman-lvm/confirm boolean true
d-i partman-lvm/confirm_nooverwrite boolean true
d-i partman-lvm/device_remove_lvm boolean true
d-i partman/choose_partition select finish